best notes in c language

Notes
Of
C
Language
By
Cj-SofTech
Opp
Punjabi Univ.
Patiala

Basics of 'C' language
Prepared By: CJ SofTech [Charanjiv Singh 98156-18658]
Coaching Of C,C++,C#, Java, Blue J, VB, VB.NET, Oracle, Data Structure And Project Work
2
C Language Programs
S.no Name of the Program
Simple programs(1 to 15)
1. WAP print “hello”.
2. Write a program to add two numbers. (without scanf()).
3. Write a program to add, multiply, divide, subtract two numbers. (Without
scanf()).
4. WAP to find out simple interest. (Without scanf()).
5. WAP to enter 5 subjects’ marks and calculate total marks and percentage.
(With scanf()).
6. Write a program to give name of item, cost, qty and calculate total bill.
7. Write a program to input marks and calculate total marks and the
percentage.
8. Write a program to input the length and breadth of rectangle to calculate
its area.
9. Write a program to calculate d=(b*b)-4*a*c/quadratic equation.
10. Write a program to convert centigrade to Fahrenheit.
11. Write a program to input five ages and find the average.
12. Write a program to swap two numbers without third number.
13. Write a program to swap two numbers with third number.
14. Write a program to input radius and find the area of circle.
15. Write a program to print int,float values using format specifiers.
Conditional Statements
Simple If(16-21)
16. Write a program to find the smallest from two numbers.
17. Write a program to input age of a person and find whether he/she is
eligible for voting or not.
18. WAP to Input marks in three subjects calculate total marks and
percentage if per>=50 then print pass else fail.
19. Write a program to input a number and find whether it is –ve or +ve.
20. Write a program to find whether a given number is odd or even.
21. Write a program to find whether the year is leap or not.
Nested If (22-27)
22. Write a program to find greatest from three integers.
23. Input age of a person conditions are
if age<12 then child if age between 12 to 25 then young if age between
25to 50 then adult if age >=50 old.
24. WAP to calculate the division of a student after getting valid marks for
three subjects with the conditions that percentage>60 is First division,
percentage<60&>40 is second division, percentage<40 is third division.
25. Input basic pay and calculate total pay (basicpay+bonus) conditions are
Pay<1000 then bonus 10% if pay between 1000 to 3000 then bonus 9% if
pay between 3000 to 5000 then bonus 8% if pay>=5000 then bonus 7% .
26. Input two nos and a choice if choice is ‘a’ add it if choice is ‘s’ subtract it

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and if choice is ‘d’ divide it otherwise give message wrong key pressed.
Looping programs
While loop (28-30)
27 Write a program to print name ten times.
28. Write a program to print series from 1 to 10.
29. Write a program to print sum of first five natural numbers.
30. Write a program to count odd numbers from 1 to 100.
do while (31-33)
31. Write a program to print series 2,4,8/3,9,27
32. Write a program to print the series up to n-2..
33. WAP to count even numbers between two numbers given.
For loop(34-36)
34. Write a program to print
9
99
999
9999
35 Write a program to print
10
101
1002
10003
36. Write a program to print
1
12
123
1234
Important Looping Programs(37-43)
37. WAP to find whether a given number is Palindrome or not.
38. Write a program to print fibbonacci series.
39. Write a program to print table of a given number.
40. Write a program to print the sum of even numbers up to n.
41. Write a program to print the sum of squares of even numbers up to n.
42. Write a program to print the factorial of a given number.
43. Write a program to check whether a given number is prime or not.
More Problems of Loops and Nested Loop (44-51)
44. Write a program to print the series of prime numbers up to n.
45. Write a program to print prime numbers between two numbers.
46. WAP to print Armstrong numbers upto 1000.
47. Write a program to enter number in octal and convert it into decimal.
48. Write a program to enter a number in decimal and change it into octal.
49. Write a program to change from binary to decimal.
50. Write a program to decimal to binary.
51. WAP to print table of given number entered by the user AND also check
for prime number.
Strings(52-56 )
52. Write a program to change the string from upper to lower case.

4
53. Write a program to reverse the given string.
54. Write a program to concatenate two strings.
55. Write a program to find whether a given string is palindrome or not.
56. Write a program to count a specific character in a word.
57. WAP to find length of a string.
58. WAP to find number of vowels, whitespaces in a string.
Arrays
Single Dimensional arrays(57-65
59.
Write a program find biggest and smallest element in array.
60.
Write to merge two arrays with same size.
61. Write a program to insert an element in an array at a specific location.
62. Write a program to sort an array.
63. Write a program to input name and age of a person and print name once
and age three times.
64. Write a program to search a given element from an array.
65. Write a program to count the number of occurrences of a given number in
an array.
Multidimensional arrays(66-72)
66.
Input the value of 3*3 matrices and display it input days of a week and
display it.
67. Write a program to add two matrices.
68. Write a program to subtract two matrices.
69. Write a program for matrix multiplication.
70. Write a program to find the sum of diagonal elements of a matrix.
71. Write a program to find the transpose of a given matrix.
72. WAP to find a specific word from string.
Structures and Unions(73-76)
73.
Write a program to input the name and roll no of ten students and print it
using structures
74.
Write a program to input the name and roll no of ten students and print it
using Unions
75.
WAP to enter two matrices (2*2) using structures and add them.
76. WAP to enter name, age, father name, city of a student and print using
structures
Functions(77-89)
ADD TWO NUMBERS USING FUNCTIONS
77 Without arguments without return

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78 With arguments without return
79 Without arguments with return
80 With arguments with return
AVERAGE OF FOUR NUMBERS USING FUNCTIONS
81 Without arguments without return
82 With arguments without return
83 Without arguments with return
84 With arguments with return
85.
WAP to add, subtract, multiply, Divide using Functions.
86. Input basicpay ,ta, da and calculate total pay with return with argument .
87.
Write a program to pass array as an argument to a function.
88. WAP to find the factorial of a given number using recursion.
89
WAP to find the sum of the digits of a given number using recursion.
Pointers(90-92)
90.
Write a program to find largest among n numbers using pointers and
arrays.
91.
Write a program to swap two numbers using pointers.
92
Multidimensional arrays and pointers and WAP to add two matrices ,
passed as arguments (as ref) using pointers.
File Handling programs(93-97)
93 Write a program to input the name and store it in a file.
94 WAP to copy the contents of one file into another.
95 Two files contains sorted lists of integers. WAP to produce a third file
which holds a single sorted, merged list of these two lists.
96 Write a program to read from and write into a file.
97
WAP that will generate a data file containing the list of customers and
their corresponding phone numbers. Use a structure variable to store the
name and telephone of each customer. Create a data file using a sample
list.
OTHER IMPORTANT PROGRAMS
98 Input 3 digits no print sum of its digits.
99 Input 3 digits no print reverse of it.
100 Print
1
12
123
1234
12345

6
Chapter 1
INTRODUCTION TO PROGRAMING LANGUAGES
Programming Languages
Programming languages are the languages used to make programs that can
be executed by the computer using compiler or interpreter. We can create
programs, application software, web sites etc with the help of these
programming languages. Programming language can be categorized as
below.
• Low Level Language.
• Assembly Language.
• High Level Language.
Low Level Language (Machine Language)
Machine Language is a language that a computer can understand, but it is
very difficult for the human beings to understand. Programs written in
machine language consist of machine instructions. Machine language
consists of strings of binary numbers (0, 1). Each microprocessor can have
different machine language.
Advantages:
1. Machine language instructions are directly executed, so there
is no compilation or translation needed, that’s why it is fast in
execution.
2. Machine language uses computer memory very well.
Disadvantages:
1. Machine language is a machine dependent.
2. It is very difficult to remember the codes.
3. Modification is difficult in machine language program.
4. High programming skills are required to develop programs in
machine language.
Assembly Language
In 1950s operation codes [opcodes] were developed. Assembler is used to
convert these codes into to machine language. Like it is difficult to
remember any code like(01010001 for add) instead of this binary code in
assembly language we use ADD to add contents of two registers.
Advantages:
1. Assembly language programs are easier to use than machine
language.
2. Error detection is possible and easy.
3. Modification is simple in assembly language program.
4. Less efforts are required as compared to machine language in
writing the program.
Assembly
language
program
Assembler Machine
language
program

7
Disadvantages:
1. These languages are fully machine dependent language.
2. Good programming skills are required to develop a program in
assembly language.
HIGH-LEVEL LANGUAGE (HLL)
High level languages are very powerful and these are similar to English
language. C, C++, Java, Visual Basic etc are the examples of HLL.
Advantages:
1. HLL are easy to learn and understand.
2. It is very easy to write the program.
3. Mostly the syntax of all high level languages are similar.
4. Knowledge of hardware is not essential to write program.
5. Program written in HLL are easy to modify.
Disadvantages:
1. Compiler or interpreter is required to convert HLL into low level
language.
2. Due to conversion these are slower in speed.
3. Specific hardware and
software are required for some high level language.
Compiler And Interpreter
Compiler and interpreter both are used to convert the high-level language
program into the object code.
Interpreter:- Interpreter convert the program of High level language into
Low level language line by line.
Compiler: - Compiler converts the whole program at a time from High level
Language into Low level language.
Features of a good programming language
Every programming language has some speciality in it, which make a
language suceesful. These specialities help languages to be popular in the
computer world. These specialities are also known as features, which are as
follows:-
1) Easy to use:- A good programming language must be simple &
easy to learn. The concept should be simple & easy to learn. The
concept should be clear & can be easily grasped. The simple languages
are easy to develop & to implement.
High level
language
program
Compiler /
interpreter
Machine
language
program
Source
code
Interpreter Object code
Source
code
Compiler Object code

8
2) Extensibility:- A good programming language should be
extended to sub-program. It increases the readability of the language.
3) Efficiency:- Programs written in a good language should be
efficient. That is, program should take less space & time to run
efficiently.
4) Better documentation :- A good programing language should
be easily understood by programmer. Coding should be precise and
logics should be upto mark.
5) Flexibility:- A good programming should have a mechanism to
control the computers CPU, memory & registers.
6) Fewer errors:- A good programming language should have
compilers & interpreters which can automatically detect syntax errors.
So these can be easily corrected by the programmer.
COMMON LANGUAGES
1) BASIC ( BEGINNERS ALL PURPOSE SYMBOLIC INSTRUCTION
CODE):- All purpose symbolic instruction ) It is designed in 1964 by
John George Kemeny and Thoman kurtic. It is easy for beginners,
provide error messasges, no need to understand hardware. Its based
on fortran-2nd
+ ALGOL.
2) ALGOL( ALGORITHM C LANGUAGE) :- Developed in 1950. It is
the first language that implement nested functions.
3) FORTRAN(FORMULA TRANSLATOR):- It is developed for
numeric computation and scientific calculation and it is developed by
IBM in 1950.
4) COBOL:- Common Business-oriented language design for
business, finance administrative systems. Cobol 2002 also support
object-oriented programming.
5) LISP:- (List processing) It is used to implement lists that is a
major data structure developed in 1958.
7) BCPL:-( Basic combine programming language) It can
perform task of many language ‘C’ is based on this language.
7) LOGO:- It gives graphics. It is develop in 1968. It is used to
create simple programs that can contain simple graphics.
8) SQL (STRUCTURE QUERY LANGUAGE):- It is used in databases
to create database and access information from it.
History Of 'C' language
Many programming languages have been created
according to the programmer requirement. In earlier
days programmer had to learn many languages to
perform different tasks. A language called
BCPL(Basic Combined Programming Language)
designed by Martin Richards of the University of
Cambridge in 1966 that perform work of many types,
this language is also known as ‘B’ language.C

9
language is the modified version of basic combined programming language
called ‘B’ Using this language Dennis Ritchie developed ‘C’ language at the
AT&T bell laboratories in 1972. It is one of the most popular computer
language.
This language is also known as High level language as it is closer to
human languages and faster from machine language.
NOTE:- C is a case sensitive language . It means uppercase alphabets are
different from lowercase alphabets e.g. ‘A’ is totally different from’a’
Why we use 'C' language
'C' was developed in 1972 but still programmers use this language due to
following reasons.
(1) C is portable means program written for one computer may run
successfully on other computers.
(2) C is fast means the executable program runs very fast.
(3) C is compact i.e. the statements written in 'C' language are
generally short and very powerful. Several operators can be used in one
statement.
(4) C language has both the simplicity of high level language and
speed of low level language, so it is also known as middle level
language.
(5) 'C' Compiler is easily available.
(6) It supports pointers that can be used to create system
programming.
(7) It can be run on UNIX operating system also.
(8) Large number of inbuilt functions are available.
(9) C has ability to extend itself. Users can add their own
functions to the c library.
(10) Program of c can be divided into small modules called
functions. These function can be reused any time by the user.
Limitations Of 'C' language or Constraints in C
(1) 'C' language does not support exception handling.
(2) Bound checking is not performed by the 'C' compiler.
(3) 'C' language does not support concepts of OOP.
(4) 'C' language does not support Unicode characters.
(5) Pointers are difficult to understand for the beginners.
C/C++ compilers
• Turbo C++
• Borland C++
• Pelles C
• Intel C++
• VisualAge C++
• Tiny 'C' Compiler
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Phases Of Software Development:
A software development process consists of various phases, each phase
ends with some defined output that become the input of next phase. The
phases are performed in a specific order. The main reason to develop
software in phases is to ensure that software should be developed in
given time and cost. Various phases to develop a program are:-
1. Requirement analysis phase: The Requirement analysis identifies
what is needed from the software. Requirements analysis is done in order
to understand the problem that will be solved by the software. This phase
bridges the gap between client and the programmer. The outcome of this
phase is the software requirement specification document (SRS). The
person responsible for the requirements analysis is often called the
analyst.
2. Software Design: The purpose of this phase is to plan a solution of
the problem specified by the SRS.
It is of two types:
• System Design or Top level Design: It identifies the various
modules that should be in the system, the specifications of the
modules and interconnections between the various modules.
DFDs[Data Flow Diagram] are the part of system design.
• Detailed Design: It identifies the internal logic of the various
modules. Data structures, algorithms, flow charts are developed in
this part of the designing phase.
3. Coding: This phase convert the design of the software into code using
some programming language. Well written code can reduce the testing
and maintenance cost and efforts.
4. Testing:- Its basic function is to detect errors in the software. After
the coding phase, programs are executed for testing purpose.
The different types of testing are:
a. Unit testing:-It tests each module separately and detects coding
errors in the module.
b. Integration testing:- When we test all modules individually, now it is
time to combine all modules with each other. Integration testing is
performed when we combine the modules with each other.
c. System testing:- In integration testing we combine all the modules
now we will test whole of the project it is known as system testing.
d. User Acceptance Testing: - This testing is performed by the user to
check whether system is created according to the needs of the user or
not.
5. Implementation: After testing, software is implemented on the
client computer to perform its actual work.
Client –server approach
Frontend:- Frontend is used by the user. The user doesn’t known anything
about the back process e.g. ATM is a machine where user is working as
frontend user. Softwares used for frontend are VB,ASP.

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Backend:- Softwares used in backend are foxpro,oracle,sql server etc.
Backend is handled & maintained by the database administrator(DBA).e.g.
ATM’s back process is controlled by the programmer.
Errors
Errors are the bugs that can produce unexpected results, mainly errors are
divided into two types.
1. Syntax errors: These errors occur due the incorrect method to
write the code. It may be due the missing comma, semi colon etc. Like
in following line, error will be displayed because string is not enclosed
in " ".
printf(hello);
2. Logical errors: These errors are not due to any syntax mistake,
but due to incorrect logic. The compiler does not show the logical
errors. Like to find average of 4 numbers if we forget to write brackets
then the result will not be according to our expectation
avg=10+20+30+40/4; in this the value of avg=70 instead of 25.
Programming techniques:-Various Programming techniques are used to
make the program simple, understandable and easy to modify. Some of the
commonly used programming techniques are:-
1. Top down design: - Using this design, program is divided into the
smaller blocks, which can be linked and called whenever needed. When it
is called it begins from the bigger block to the smaller till the program
ends.
2. Bottom up design: - It is also designed in the same manner and
divides the whole program into the smaller blocks, but when it is called it
begins from the smaller block to the bigger till the program end.
3. Modular design: - A level consists of one or more modules. Each
module performs its own task and each module has minimal contact with
other modules, so that each module can be implemented separately.
Execution is controlled by the main program
Generations Of Computer Languages
First-generation Language
First-generation language is the lowest level computer language.
Information is given to the computer by the programmer in binary form.
Binary instructions are the same as on/off signals. The language consists of
zeros and ones.
Second-generation Language
Assembly language was the second generation of computer language.
Assembly language consists of letters of the alphabet. This makes
programming much easier as compared to binary form.
Third-generation Language
These languages are similar to spoken English. Third-generation computer
languages are much easier than first two generations.
Fourth-generation Language

12
Fourth-generation languages typically consist of English-like words and
phrases. These languages can include graphic such as icons and buttons etc
.
Important Questions [Short Questions]
1. What do you mean by Programming language?
2. Write History of 'C' language.
3. What are ASCII Codes?
4. Write difference between high level language and low level
language.
5. Define compiler.
6. Define interpreter.
7. Define assembler.
8. Name various high level language.
Important Questions [Long Questions]
1. Explain phases of software development.
2. Write Applications of 'C' language .
3. Write limitations of 'C' language .
4. Advantages and limitations of High level languages.
5. Advantages and limitations of Low level language.
6. Explain errors and various types of errors.
7. Write Note on:
a. Top-Down Approach
b. Bottom-up Approach
8. Explain Various Generations of Computer language .
CJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.CJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.CJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.CJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.

13
Chapter 2
BASIC OF 'C' LANGUAGE
Before Writing 'C' Program
Before starting programming in ‘C’ Language, it is better to learn some basic
concepts like:-
1. Important logics that will be used in common 'C' programs.
2. Character set of 'C' language.
3. Constants
4. Variables
5. Keywords
6. Data types
7. Operands
8. Operators
9. How to open 'C' Compiler.
10. Compile and run 'C' program
11. Open and save 'C' program.
12. Algorithms and Flow Charts.
1. Basic Logics [Formulas]: Some of the basic formulas that we will
use in 'C' are:-
Area of Rectangle A=L*B
Area Of Circle A=3.14*R*R
Volume Of Box V=L*B*H
Average Of 3 Numbers AVG=(A+B+C)/3
Convert Fahrenheit
Temperature To Centigrade
°C = 0.56(°F – 32)
or 5/9(°F – 32)
Convert Centigrade
Temperature To Fahrenheit
°F = 1.8(°C) + 32
or ( 9/5 x °C) + 32
Area Of Square A=L*L
Area Of Triangle A=(L*B)/2
Swap A and B T=A
A=B
B=T
Discriminant of Quadratic
equation
D=B*B-4*A*C
2. Character set: A character represent alphabet, digit or special
symbol that we can use in 'C' language. In 'C' we can type mainly
three types of characters.
1) Alphabets :A to Z and a to z
2) Numbers: 0,1,2,3,4,5,6,7,8,9
3) Special Symbols : { } ” : ; [ ] ( ) + - * & ^ % < . ? , = !
# etc

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3. Constant: The value of a constant is fixed and we cannot
change the value of the constant. We use const keyword to declare
constant in 'C' language.
Types of c constants:-
'C' constants can be divided into two major categories.
a) Primary constants
Integer constants, real constants, character constants.
b) Secondary constants
Array, pointers, structures, union, enum.
4. Variables: The value of variable can be changed during the
program. Variables can be local or global.
Local variables: Local variables are defined with in the pair of braces
or between the body of the function. The scope of the variable is with in
the function.
Global variables: These variables are defined out side of all the
functions. And these variables can be used in any function with in the
file because the scope of these variables are global to the file.
Difference between constant & variable:-
5. Keywords: Keywords are the reserved words with some
specified function. The meanings of keywords are already defined in 'C'
compiler. We cannot use keywords as variable names. In C there are 32
keywords like if, for, while, void, int, float, do, break, continue,
goto, struct, enum, double etc.
6. Data types: The value stored in variable or constant depends
upon data type, or we can say Data types represent what type of data
will be stored in the variable . In 'C' language we have three basic
datatypes int(used to store numbers without decimal), float(used to
store numbers with or without decimal), char(used to store
alphanumeric characters). Data types available in C are :-
Constant Variable
1) Constant value doesn’t
change during
execution of the program.
1) Variable vary during
2) It is fixed quantity. 2) It’s value can be changed.
3)e.g. z=2x+5y
here 2,5,are constants.
3)e.g. z=2x+5y
here x,y are variables.

15
TYPE SIZE (Bits) Format Specifier Range
char 8 %c -128 to 127
int or signed int 16 %d -32768 to 32767
unsigned int 16 %u 0 to 65535
long int or signed
long int
32 %ld -2147483648 to 2147483647
unsigned long int 32 %lu 0 to 4294967295
float 32 %f 3.4 e-38 to 3.4 e+38
double 64 %lf 1.7e-308 to 1.7e+308
long double 80 %Lf 3.4 e-4932 to 3.4 e+4932
7. Operands: c=a+b, In this expression a,b,c are operands.
These are variables that store any value.
8. Operator: operators refer to symbols that represent a particular
operation to be performed on data. Types of operators are:-
Assignment operator: Assignment operators are used to assign the
values to a variable. Assignment operators are (+=,-=,/=,*= etc).
Arithmetic operator: These are used to perform arithmetic
calculation on the operands. Arithmetic operators are +,-,*,/,%.
Relational operator: Use to check relation between operands. E g.
>,<,<=,>= etc.
Logical operator: These operators are used to attach more than one
relational operator in one statement. These are &&(AND), ||(OR),
!(NOT).
Conditional operators: These are used when we want to execute the
statements according to the condition.
Bitwise operators:Bitwise operators are special operators designed
to work on the bit level.
Bitwise
Operator
Meaning
& Bitwise AND
| Bitwise OR
^ Bitwise exclusive OR
<< Shift left
>> Shift right
~ One’s complement

16
9. How to install c into your computer:-
1) First of all , find turboc .exe file.
2) Copy this file and paste it on c:drive.
3) Now, open DOS prompt.
4) Type cd and press enter.
5) C:turboc.exe –d. It will extract all directories from turboc c to
your c drive.
10. How to open 'C' Compiler.
If you are writing program in windows98, 2000,2003,XP then you can
use any compiler of 'C'. But if you use windows vista or window 7 then it
is better that you use 32-bit or 64-bit Compiler according to the
operating system.
Steps to open 'C' compiler
1. Select Run from start and type command or cmd in run
box.
2. At DOS Prompt type [if 'C' is installed in c drive]
cd
cd tc
cd bin
tc

17
3. With these commands 'C' editor will open that look like
To maximize use alt+enter
4. To start new program select new from file menu
5. Following screen is displayed to type program.

18
11- Compile and run 'C' program
To compile the program select compile option from the Compile menu or
Press Alt + F9
To run the program select run option from the run menu or Press Ctrl + F9
12. Open and save 'C' program.
To open a file select open from file menu or press F3, and to save
select save form file menu or press F2,the extension of 'C' program is
.c
Steps to take C programs in printed form:
1) Go to c:tcbin and press enter.Right click on the file having
extension .c or .cpp and open it with notepad.
2) Now go to file menu of notepad & click on print option.
3) The printed form of required C program will be in your hands.
Algorithms
Algorithms are the English like steps to solve a problem. It is the part of
software designing. Before creating a program or software we develop its
design using some tools like algorithms, DFDs, Flowcharts etc. Mainly we
follow following steps to design an algorithm.
Step 1. START //it represents beginning of the algorithm
Step 2. DECLARE //the variables used in algorithm are declared in this step.
Step 3. INPUT // here we input the values
Step 4. FORMULA// the required result is generated in this step.
Step 5. OUTPUT // display the result.
Step 6. STOP // end of algorithm
**We can use if else, goto ,loops etc according to requirement
Flowchart:-

19
A flowchart is pictorial representation to solve a problem. It is the graphical
representation of an algorithm. Also we can say that these are the symbolic
diagrams which tells the user about the data flow, sequence and processing
logic in information processing.
We can use following symbols to create flowchart
Symbol Symbol Name Symbol Description
Process
Show a Process or action step. Any kind of
processing like mathematical calculations are
depicted using processing box. It is nothing but
a rectangle which indicates processing.
Flowline
(Arrow)
Flow line shows the direction of flow of control.
Decision Decision box is used when there are 2 options
(Yes/No). It is used as if-else. It is used to take
any decision in the program. It returns the
value in true or false.
Connector Connector connects the various portion of the
flowchart.A connector is used when the flowchart is
split between two pages
Input/output This is used to input and print data .
Terminator It represents starting and ending point of the
flowchart. We use start & stop option in it. The
shape of terminal symbol is in oval shape.
Algorithm
Step 1: START
Step 2: PRINT “hello”
Step 3: STOP
Flowchart
Q1. Write an algorithm and draw flowchart
PRINT
START
STOP

Basics of 'C' language Page No: 20
Q2. Write an algorithm and draw flowchart
to add 2 numbers. Flowchart:->
Algorithm :
Step 1: START
Step 2: DECLARE A,B,C
Step 3: A=10
Step 4: B=20
Step 5: C=A+B
Step 6: PRINT C
Step 7: STOP
Q3. Write an algorithm and draw
flowchart to add, sub, mul, div
2 numbers.
Algorithm
Step 1: START
Step 2: DECLARE A, B, ADD, SUB,
MUL, DIV
Step 3: INPUT A, B
Step 4: ADD A+B
Step 5: SUB A-B
Step 6: MUL A*B
Step 7: DIV A/B
Step 8: PRINT “SUM=”, ADD
Step 9: PRINT “SUB=”, SUB
Step 10: PRINT “MUL=”, MUL
Step 11: PRINT “DIV=”, DIV
Step 12: STOP
DECLARE A,B,C
C=A+B
PRINT C
A=10
B=20
START
STOP
START
Declare A, B, SUM, SUB, MUL,
DIV
INPUT A,B
PRINT “SUM=”, ADD
PRINT “SUB”, SUB
PRINT “MUL=”, MUL
PRINT “MUL=”, MUL
STOP
ADD = A+B
SUB = A-B
MUL = A*B
DIV = A/B
CJ SOFTECH Walia Enclave Opp Punjabi UnCJ SOFTECH Walia Enclave Opp Punjabi UnCJ SOFTECH Walia Enclave Opp Punjabi UnCJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.iv Patiala.iv Patiala.iv Patiala.

Q4.Write an algorithm and draw flowchart
to find greatest among two numbers.
Algorithm
Step 1: START
Step 2: DECLARE A, B
Step 3: INPUT A, B
Step 4: IF A>B THEN GOTO STEP 5 ELSE GOTO STEP 6
Step 5: PRINT “A IS GREATEST” GOTO 7
Step 6: PRINT “ B IS GREATEST”
Step 7: STOP
Y
Pseudo code:-Pseudo code is like an algorithm but pseudo codes are nearer
to the program. It is the outline of the program and it cannot be compiled
nor executed. It is easy to covert Pseudo code into program as compare to
algorithm.
TOKENS:-The individual words ,special symbols , operators, punctuation
marks are called tokens.These are given below:
Keywords
Constants
Operators
Identifiers
Special
symbols
Strings
C
Tokens
START
DECLARE A,B
INPUT : A, B
IF
A>B
then PRINT: A IS
BIG
PRINT: A IS
BIG
STOP
N
CJ SOFTECH Walia Enclave Opp Punjabi Univ PatialaCJ SOFTECH Walia Enclave Opp Punjabi Univ PatialaCJ SOFTECH Walia Enclave Opp Punjabi Univ PatialaCJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala

COMMENTS:These are the statements which are not executed by the
compiler . It means that these statements are ignored by the compiler.
Comments can be of two types:-
1) Single line comments
2) Multi line comments
Single line comments:- Single line comments are used to display any
statements for understanding of the user.It can be used by using double
slash (//) symbols.
e.g. //Single line comments
Multi line comments:- When user wants to write number of statements for
knowledge of the user,but ignored by the compilers then we use multi line
comments.
e.g. /*-----------------
------------------*/
Important Questions [Short Questions]
1. Define Character set Of 'C' language.
2. Define Constant and Variables.
3. Define Keywords.
4. Define Data types.
5. Define Operand and Operators .
6. How we can open 'C' compiler and run our program?
7. Write Difference between ‘a’ and “a”.
8. What are shorthand or shortcut or short circuit assignment
operators?
Important Questions [Long Questions]
1. Define algorithms and basic structure of an algorithm.
2. Define Flowchart and symbols used in it.
3. Explain basic Data types of 'C' language.
4. Write algorithm and draw flowchart to find simple interest.
5. Write an algorithm to find roots of the quadratic equation.
6. Explain operators present in 'C' language.
# 3058# 3058# 3058# 3058 UrUrUrUrban Estate Phaseban Estate Phaseban Estate Phaseban Estate Phase –––– 2 Patiala2 Patiala2 Patiala2 Patiala

Chapter 3
START PROGRAMING IN 'C' LANGUAGE
As we discuss we can use various approaches to develop software. Today
languages are based on two main concepts Procedural Programming and
Object Oriented Programming. ‘C’ is procedural language and ‘C++, Java’
are Object Oriented languages. In procedural language functions are
created to perform various tasks. Functions can be inbuilt or user defined
and in object oriented language classes are created. Classes are the
combination of functions and data.
'C' language is a procedural language where every thing is done in the form
of functions. In 'C' language we have two main types of functions
1. Inbuilt
2. User defined functions.
Inbuilt functions are pre defined in the 'C' compiler and we use them
according to the requirement, work of inbuilt functions are fix. With the help
of inbuilt functions and statements we create user define functions. 'C'
program can contain any number of user define functions. But one of them
must be main function. Main function is the entry point of the program,
compiler run the working of program from main function, all the other
functions are directly and indirectly called by the main function.
Basic Structure of 'C' program
Explaination of Basic structure of ‘C’
HEADER FILES:These include all the library functions,macros, it contains
inbuilt functions like printf , scanf , getch etc.In C there are 24 header files.
Global Variable declaration

PREPROCESSOR DIRECTIVE:- It instructs the C compiler to add contents
of an include file into program during compilation. Include files should have
.H extension
e.g #include<stdio.h>
GLOBAL VARIABLE DECLARATION:- There are some variables which are
used in different function.It is better to declare such variables outside of all
the functions.These variables are called global variables.
MAIN FUNCTION SECTION:- Every program of C must have one main()
function. All statements written under this function must appear between the
opening & closing braces.
FUNCTION DEFINITION:- This section contains all user defined
function.These user-defined functions are always called in the main function.
Rules to create a program in 'C' language.
1. Each statement mostly ends with a semicolon (;).
2. The statements in a program must be written in
the same order in which we want to execute them.
3. All statements are written in small letters.
4. Every program must have main function.
5. clrscr() function should be written after variable declaration.
6. Program should be saved with the extension .c .
Some important functions
An ISO C standard libraries is made of 24 header files, which can be used
into a program. Each header file contains one or more functions and macros,
it contain inbuilt functions. In beginning we mainly use only two header files.
1. stdio.h : standard input output header file, it contains functions to
input data in the program and take output from the program. Eg printf(),
scanf() functions etc
2. conio.h : console input output header file, it also contains some
additional input output functions.
Eg getch(),putch(),clrscr() etc
printf():- printf function is used to take output from the
program.
scanf():- scanf function is used to give input in the program.
clrscr():- used to clear the screen.
getch():- To input a character.
What is a Program?
It is defined as the set of instructions that we give to computer as input
through keyboard. Program is also known as passive entity and program in
execution is called active entity.
Before writing program in 'C' language, it is always better that we write an
algorithm of it. [Especially when we are new in programming]. In this book
we write algorithms with the some programs so that beginners can
understand programs easily.
Write algorithm and program to print “hello world”

Step1 Start
Step2 Print “hello world”
Step3 Stop
To write a program from algorithm, we step by step convert the steps into
program.
Algorithm Program
Step1 Start void main()
{
Step2 Print “hello world” printf(“hello world”);
Step3 Stop }
When we use inbuilt function in the program it is better to include header
files of that functions like printf function is define in stdio.h so we include
this file in our program. The program become like this.
We compile the program with alt+F9. It displays errors. After removing the
errors we can run the program using Ctrl+F9.Complier runs the program and
control come back to the editor screen, we can use Alt+F5 to view result.
Output:- hello world
If a program work on some variables then we need to declare these
variables with the help of data types. We need to follow some rules to
declare variables.
The variables should be declared before clrscr() function.
Use variable names that mean something. Single-letter variables
are difficult to understand so it is better to use long names like
index is better than i, count is better than c, and name is better
than n.
Variables are typically in lowercase. They can contain letters and
numbers.
Uppercase letters can be used in variable names.
You should not begin a variable name with a number. They can
contain numbers, but you begin it with a letter.
"underscore" character can be used in variablenames like
first_name, roll_no etc.
We can not use keywords as variable names eg variable name
like int,if,float are invalid.
We can not create more than one variable with same name in
same scope.
#include<stdio.h>
void main()
{
printf(“hello world”);
}

Write algorithm and program to print sum of two numbers
Step1 Start
Step2 declare a,b,c
Step3 a=10
Step4 b=20
Step5 c=a+b
Step6 Print c
Step7 Stop
.Algorithm Program
{
Step2 declare a,b,c int a,b,c;
Step3 a=10 a=10;
Step4 b=20 b=20;
Step5 c=a+b c=a+b;
Step6 Print c printf(“%d”,c);
Step7 Stop }
In printf we need format specifier to print value of the variable like we use
%d to print value of variable c. Some times we use getch() to avoid pressing
Alt+F5. and clrscr() function if we want to clear the screen. clrscr() function
should be used after the variable declaration.
Output:- 30
If we write printf function like :- printf(“sum=%d”,c);
Output:- sum=30
Write algorithm and program to swap two numbers
Step1 Start
Step2 declare a,b,c
Step3 a=10
Step4 b=20
#include<conio.h>
#include<stdio.h>
void main()
{
int a,b,c;
clrscr();
a=10;
b=20;
c=a+b;
printf("%d",c);
getch();
}

Step5 c=a
Step5 a=b
Step5 b=c
Step6 Print a
Step6 Print b
Step7 Stop
Algorithm Program
{
Step2 declare a,b,c int a,b,c;
Step3 a=10 a=10;
Step4 b=20 b=20;
Step5 c=a c=a;
Step5 a=b a=b;
Step5 b=c b=c;
Step6 Print a printf(“%d”,a);
Step6 Print b printf(“%d”,b);
Step7 Stop }
Output:- a=20 b=10
scanf function:- It is used to take input from the user. It contain
format specifiers and variables. Eg:- scanf(“%d”,&a);
%d is format specifier, & is address operator and a is a variable name
which store value that we enter.We can also enter more than one
variable in scanf function like
scanf(“%d%d”,&a,&b);
Qualifier :-It give properties to an identifier. The const type qualifier
declares an identifier to be fixed [not changeable]. The volatile
qualifier declares an identifier whose value can rightfully be changed.
#include<conio.h>
#include<stdio.h>
void main()
{
int a,b,c;
a=10;
b=20;
c=a;
a=b;
b=c;
printf("a=%d ",a);
printf("b=%d ",b);
getch();
}
# 3058# 3058# 3058# 3058 Urban Estate PhaseUrban Estate PhaseUrban Estate PhaseUrban Estate Phase –––– 2222 PatialaPatialaPatialaPatiala

Write algorithm and program to enter two numbers and print
sum of these numbers.
Step1 Start
Step2 Declare a,b,sum
Step3 Print “Enter value of a”
Step4 Input a
Step5 Print “Enter value of b”
Step6 Input b
Step7 sum=a+b
Step8 Print sum
Step9 Stop
.Algorithm Program
{
Step2 declare a,b,sum int a,b,sum;
Step3 Print “Enter value of a” printf(“Enter value of a”);
Step4 Input a scanf(“%d”,&a);
Step5 Print “Enter value of b” printf(“Enter value of b”);
Step6 Input b scanf(“%d”,&b);
Step5 sum=a+b sum=a+b;
Step6 Print sum printf(“%d”,sum);
Step7 Stop }
In this program we use format specifier %d for int in scanf function.
Output:- Enter value of a 10
Enter value of b 20
Sum=30
*10 and 20 will be entered by the user through keyboard
We can use float, long, double data types according to the
requirement. And if we want to work on characters we use char data
type.
#include<conio.h>
#include<stdio.h>
void main()
{
int a,b,sum;
printf("Enter value of a ");
scanf("%d",&a);
printf("Enter value of b ");
scanf("%d",&b);
sum=a+b;
printf("sum=%d",sum);
getch();
}

Write a program to input and print a character.
Output:
Enter a character G
character =G
We can also assign a character without scanf function, but character
should be in single quotes like ‘a’ ‘F’ etc
Output:- character=A
The Escape Sequences
Escape Sequences are used for formatting the output string mainly written in
printf(). It consists of backslash followed by a character. The character
sequence is always enclosed in the control string. Various escape sequences
are
n the next line character
t tab position
a used for sound
r carriage return
b shifts cursor one position left
#include<conio.h>
#include<stdio.h>
void main()
{
char ch;
clrscr();
printf("Enter a character ");
scanf("%c",&ch);
printf("character=%c",ch);
getch();
}
#include<conio.h>
#include<stdio.h>
void main()
{
char ch;
clrscr();
ch='A';
printf("character=%c",ch);
getch();
}

Without any Escape sequence:
printf(“hellobye”);
Output:
hellobye
With n Escape sequence:
Using n the output will be shifted to next line
printf(“hellonbye”);
Output:
hello
bye
With t Escape sequence:
Using t some space[TAB]will be displayed before printing next
information
printf(“hellotbye”);
Output:
hello bye
With b Escape sequence:
After b one character from the left of b is deleted
printf(“hellobbye”);
Output:
hellbye
With r Escape sequence:
Using r position of the cursor come to the beginning of the line.
printf(“hellorbye”);
Output:
byelo
With a sequence:
It produce beep sound.
printf(“helloabye”);
Output:
hello[beep sound]bye
I/O functions in 'C' language
Input/Output means to receive data from any input device and send
data to the output device respectively.
I/O functions can be classified into two types:
1. Disk I/O functions: These are the functions that perform I/O
operations on secondary storage device like floppy, hard disk etc.
2. Console I/O functions: These are the functions that receive
input from keyboard and write output to screen. These functions
are further classified into two types:
a. Unformatted I/O Functions
b. Formatted I/O Functions

Unformatted I/O Function
1. getch(): When we type a character, the character would not be
displayed on the screen but it is assigned to a variable immediately
without pressing enter button from the keyboard.
For e.g.
char A:
A=getch();
2. getche(): When we type a character, the character is displayed
on the screen and assigned to a variable immediately without
pressing enter button from the keyboard.
For e.g.
char A:
A=getche();
3. getchar(): The typed character is displayed on the screen but it
is assigned to a variable when we press enter button from the
keyboard.
For e.g.
char A:
4. A=getchar();
5. gets(): It is used to input string. We can also input spaces
between the various words of the string.
6. putch() or putchar(): These functions are exactly the same and
use to print a character to screen.
7. puts: It is used to print the string on the monitor.
Formatted I/O Functions
1. scanf(): In scanf we can input integer, float, char, string
simultaneously. The limitation of this function is that we cannot
enter space between the words of the string.
2. printf(): This function is used to display values of int, float or
plain messages to the user. Syntax is:
printf(“format string”,variablelist);
Type casting Or Type conversion
It is used to convert the one data type into another temporarily. It can
be implicit or explicit. Implicit type conversion is automatically
performed by the computer and explicit type conversion is performed by
the programmer.
void main()
{
int a=5;
float b;
b=a/2;
printf(“b= %f”,b);
}
Output:- b= 2.000000
void main()
{
int a=5;
float b;
b=(float)a/2;
printf(“b= %f”,b);
}
Output: b=2.500000

Important Questions and programs[Short Questions]
1. Explain printf and scanf functions.
2. Explain the use of clrscr function.
3. Write a program to convert centigrade temperature into
Fahrenheit temperature.
4. Write a program to swap two numbers with third variable.
5. Write a program to swap two numbers without third variable.
6. Write rules to create a simple 'C' program.
Important Questions and programs[Long Questions]
1. Write a program to print sum of digits of two digit number.
2. Write a program to reverse a three digit number.
3. Write a program to input cost and quantity. Give 10% discount
on total bill
4. Input marks in four subjects of a student. Print total and average
marks.
5. Explain escape sequences.
6. Explain various input output functions.
7. Explain Structure of the 'C' program.
8. Write various rules for variable declaration.
** Perform Programs from 1 to 15 from program list

Chapter 4
OPERATORS
Operators are the symbols that are used to perform various operations on
data, like arithmetic operations, comparison or logical operations
etc.Operator refers to a symbol that tells the computer to perform certain
mathematical or logical tasks on operands. Operators can be Unary and
Binary. Unary Operators work on one operand like –a, b++ etc and
Binary operators work on two operators like a+b, a*c etc.
C provides different types of operators as follow:-
1) Arithmetic operators
2) Logical operators
3) Assignment operators
4) Relational operators
5) Bit wise operators
6) Unary operators
7) sizeof operator
8) Comma operator
9) Conditional operator
These operators are performed on operands and operands are the variables
on which these operations are performed.
e.g x+y
In this x,y are operands and + is operator and x+y is called expression.
1). Arithmetic operator:- These operators are used in arithmetic
operations. C provides all the basic arithmetic operators like +,-,*,/,%. The
modulus(%) operator tells us what would be the remainder after integer
division.
NAME SYMBOL IN C
Addition +
Subtraction -
Multification *
Division /
Modulus %
Arithmetic operators are classified into 3 categories :-
a) Integer arithmetic:-When arithmetic operators are performed on two
integers i.e a,b are integers , then the expression is known as an integer
expression and this operation is called integer arithmetic.
e.g. if a & b are integer like a=9,b=4
then
a+b=13
a-b=5

a*b=36
a/b=2 (decimal ignored as it is an integer arithmetic)
a%b=1 (remainder)
b) Real arithmetic:- The Operators which are performed only on real
operands, called real arithmetic. Real operands may include decimal or
exponential notation.
e.g a=9.0 and b=4.0
then a/b=9.0/4.0=2.250000
NOTE:- The operation % cannot be used with real operands.
c) Mixed mode arithmetic:- It is the combination of real operand &
integer operand. In this case if either operand is of real type then result will
always be is a real no. e.g 25/10.0=2.5
whereas 25/10=2
2) Logical operators: - The logical operators && and || are used when we
want to test more than one condition to make decisions. The result of logical
operator AND (&&) will be true only if both the conditions are true, whereas
the result of a logical operator OR (||) will be true if one or more conditions
are true. In other words, the result of a logical OR operation will be false
only if all conditions are false.
logical operators
e.g. 1) (age>18 && age<=25)
2) (number<0 || number>10)
LOGICAL AND (&&)
AND (&&) is a logical operator that will give result if and only if all of its
conditions are true.
Condition1 Condition2 Result Value
False
False
True
True
False
True
False
True
False
False
False
True
0
0
0
1
LOGICAL OR (||)
OR (||) is a logical operator that will give result if minimum one of its
condition is true.
NAME SYMBOL IN 'C'
AND &&
OR ||
NOT !

Condition1 Condition2 Result Value
False
False
True
True
False
True
False
True
False
True
True
True
0
1
1
1
LOGICAL NOT (!)
NOT (!) is a logical operator that convert true into false and false into
true.
Input Output Value
False
True
True
False
1
0
3)Assignment Operators: - It is used to assign value to the
variable. Value can be any constant value or evaluation of an expression.
It evaluates the expression on right hand side and then assigns the value
to a variable on the left hand side. Some assignment operators are:
OPERATOR EXAMPLE MEANING
+= X+=4 x=x+4
-= y-=3 y=y-3
*= Z*=4 z=z*4
/= p/=9 p=p/9
%= i%=2 i=i%2
e.g a=4 //assigns value 4 to variable a
x=a // assigns value of a to x
z=a+x //performs addition & assigns result to z
4) Relational Operators:- The relational operators are used to
check the relation between two operands. These are used to compare
two different quantities and then to take decisions e.g we may
compare salary of two employees , age of two students and so on. It
can be done by using relational operators. These operators are used
with decision making statements such as if-else, for , while etc.
e.g. let a=1,b=5
then a<b is true
but
b<a is false
It means the result of relational operators is returned as either true or false
i.e.1 or 0.

NAME 'C' SYNBOL
Greater than >
Less than <
Equal to ==
Not equal to ! =
Greater than or equal to >=
Less than or equal to <=
5) Bit Wise Operators: -These operators are used for testing the
bits, or shifting them right or left. These operators are used for
manipulation of data at bit level.
1. Bit wise logical operators
a. Bit wise and (&)Bit wise or (|)
b. Bit wise xor ( ^ )
2. Bit wise shift operators
a. Bit wise left(<<)
b. Bit wise right(>>)
3. Complement operator(~)
Operator Meaning
& Bit wise Logical AND
| Bit wise OR
^ Bit wise XOR
<< Left shift
>> Right shift
~ Complement
#include<stdio.h>
#include<conio.h>
void main()
{
int n,m,and,or,com,rs,ls,xor;
n=11;
m=5;
and=n&m;
or=n|m;
xor=n^m;
com=~n;
ls=n<<2;
rs=n>>2;
printf("n n&m=%d",and);
printf("n n|m=%d",or);

printf("n n^m=%d",xor);
printf(“n ~n=%d",com);
printf("n rs>>2=%d",rs);
printf("n ls<<2=%d",ls);
}
Output:-
n&m=1
n|m=15
n^m=14
~n=-12
rs>>2=2
ls<<2=4
How Bitwise operators produce this result?
[in description we assume int is of 8 bit or 4 bit. But in 'C' language
integer is of 16 bits]
The binary of n(11)= 00001011
The binary of m(5)= 00000101
a. n&m
1011
0101
0001 which is=1 so n&m=1
b. n|m
1011
0101
1111 which is=15 so n|m=15
c. n^m
1011
0101
1110 which is=14 so n^m=14
d. ~n
00001011
complement of this is 11110100 which =-12 in 2’s compliment system
e. n<<2
00001011 when we shift 2 bits left then value=00101100
Which is=44 so n<<2=44
f. n>>2
00001011 when we shift 2 bits right then value=00000010
Which is=2 so n>>2=2
6) Increment / Decrement operators:- The increment
operators increase the value of an operand by 1 and decrement
operator decrease the value of an operand by 1.It is of types: -
a) Increment (++)
b) Decrement (- -)
Example

int a=5;
a++:
printf(“%d”,a);
Output is 6 means ++ operator increase the value by 1.
Example
int a=5;
a--:
printf(“%d”,a);
Output is 4 means -- operator decreases the value by 1.
Increment or Decrement operators are further two types: -
1) Pre increment operator/Pre Decrement operator
2) Post increment operator/post Decrement operator.
Both operators increment or decrement the variables but at different times.
The statement ++x increments x before using its value, while x++
increments x after its value has been used.
The x++ or x-- reads the value & store a copy of it at temporary location.
The computer increments or decrements the variables, & the temporary
copy is used in expression.
e.g.
int x,y;
x=5;
y=x++;
printf(“x=%d,y=%dn”,x,y);
o/p :-
x=6,y=5
Example of pre increment operator
#include<stdio.h>
#include<conio.h>
void main()
{
int a=5,b;
b=++a;
printf(“na=%d”,a);
printf(“nb=%d”,b);
getch();
}
output:- a=6
b=6
Example of post increment operator
#include<stdio.h>
#include<conio.h>
void main()
{
int a=5,b;

b=a++;
getch();
}
output:- a=6
b=5
Example of pre decrement operator
#include<stdio.h>
#include<conio.h>
void main()
{
int a=5,b;
b=--a;
getch();
}
output:- a=4
b=4
Example of post decrement operator
#include<stdio.h>
#include<conio.h>
void main()
{
int a=5,b;
b=a--;
getch();
}
output:- a=4
b=5
7) sizeof operator: - The sizeof operator returns the size , in
bytes , of the given operand. A sizeof operator is a unary operator that
returns the number of bytes required to store a variable or a data
type.
Syntax is:-
sizeof(datatype or variable)
Example:-
sizeof (int)

Write a program to find the size of int , float and char.
#include<stdio.h>
#include<conio.h>
void main()
{
int a;
float b;
char c;
printf("n size of int =%d bytes",sizeof(a));
printf("n size of float=%d bytes",sizeof(b));
printf("n size of char =%d byte",sizeof(c));
getch();
}
Output
size of int =2 bytes
size of float=4 bytes
size of char=1 byte
8) Comma operator: - The comma operator (,) is used to declare more
than one variable in single line. It is also known as separater as it separates
one variable name from other.
Example
int a,b,c;
9) Ternary operator: - Ternary operator is also known as conditional
operator or immediate if. These are ? and : ternary operator. An operator
that takes three statements to work. The syntax of this operator is
<Condition>? <Expression1>: <expression2>
The <condition> is evaluated first. If the result is true then expression 1 is
executed, otherwise expression 2 is executed.
If <condition> is false ,expression3 is evaluated & its value becomes the
result of expression.
e.g. if a=15,b=5
x=(a>b)?a:b
The above example means that if a is greater than b then a will be assigned
to x, otherwise b will be assigned to x.
It can be achieved using if-else statements as follows:
if(a>b)
x=a;
else
x=b;
Note:The detail of if-else is discussed in next chapter.

Operators precedence and Associativity
Operators
Associativity
( [ - . Left to right
! - ++ -{- + * & (type-cast) sizeof Right to left
* / % Left to right
+ - Left to right
<< >> Left to right
< <= > >= Left to right
== != Left to right
& Left to right
^ Left to right
| Left to right
&& Left to right
|| Left to right
?: Left to right
= += -= *= /= %= Right to left
&= ^= |= <<= >>= Left to right
Important Questions[Short]
1. Define relational operators.
2. Explain Advance assignment operator.
3. Define Ternary operators.
4. Define sizeof operator.
5. Write difference between logical AND and OR operators.
6. Write difference between ++I and I++.
Important Questions[Long]
1. Explain Bitwise operators.
2. Explain increment and decrement operators with example.
3. Write precedence of the operators.
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Expression
Statement
Or Statements
true
false
Chapter 5
CONDITION CONTROL STATEMENTS
Control Statements
Normally program is executed in the sequential order, and when we want to
change the normal execution of the program then we need to use control
statements or we can say control statements are used to change the normal
Control statements are mainly divided into three types
1. Condition control statements
2. looping or iterative statements
3. branching statements
1. Condition control statements
These are used when we want to execute the statement or block of
statements according to some condition. Conditional execution can be
controlled by :-
a. if
b. if else
c. if else if
d. Nested if
e. switch case
f.Conditional operator or ternary operator
If Statement
It is the basic condition control statement. When we have single
condition then we mostly use it. The if statement allows a programmer
to test the value of a conditional expression and to select or reject the
execution of the statement or block of statements depending on this
value.
Syntax of if:
if (condition)
{
statement1;
statement2;
}
Statement1 and statement2 will only execute if the
condition is true
RULES TO USE IF STATEMENT
o The IF condition ends with a pair of parenthesis
o There is no semicolon after the parenthesis

1. Write an algorithm and program to Input age and print “you
are child” if age <10.
Algorithm Program
{
Step2 declare age int age;
Step3 Print “Enter age” printf(“Enter age”);
Step4 Input age scanf(“%d”,&age);
Step5 if age< 10
then
Print “You are child”
End
if(age<10)
{
printf(“You are child”);
}
Step7 Stop }
2. Write an algorithm and program to Input a number and
print its absolute value.[eg absolute value of 10 and -10 is 10,
it is non negative value]
Algorithm Program
{
Step2 declare a int a;
Step5 if a< 0
then
a=-a.
End
if(a<0)
{
a=-a;
}
Step6 print a printf(“%d”,a);
Step7 Stop }
Output:-
1. Enter value of a 22
22
2. Enter value of a -22
22
* when we enter 22 if block is not executed and when we enter -22 if block
convert this -22 to 22.
In above program if we enter negative number then if block will executed
and convert negative number to positive number.

Expression
Statement1 Statement2
true false
IF ELSE
If is a single selection structure and if else is a double-selection structure
because it selects from two different actions. If else is one of the most
commonly used control statement.
Syntax
if (Expression)
statement1
else
statement2
If Expression is true then it executes statement1 otherwise it executes
statement2
Write an algorithm and program to Input two number and print
greatest from them.
Algorithm Program
{
Step2 declare a,b int a,b;
Step5 Print “Enter value of b” printf(“Enter value of b”);
Step6 Input b scanf(“%d”,&b);
Step5 if a> b
begin
Print “a is big”
End
Else
Begin
Print “b is big”
End
if(a>b)
{
printf(“a is big”);
}
else
{
printf(“b is big”);
}
Step7 Stop }
Output:-
Enter value of a 20
Enter value of b 10
a is big

In above program “a is big” will be printed if a is greater than b else
result will be ”b is big”.
What happen if a=b?
In above program if we input same values in both the variables then
output will be “b is big”. To overcome this we need to create three blocks.
#include<stdio.h>
#include<conio.h>
void main( )
{
int a,b;
clrscr();
printf("enter the value of a");
scanf("%d",&a);
printf("enter the value of b");
scanf("%d",&b);
if(a>b)
{
printf("a is big");
}
if(b>a)
{
printf(" b is big");
}
if(a==b)
{
printf(" a is equal to b ");
}
getch();
}
If Else If ladder
If we have more than two conditions then we use if else if statement . In
this we can create multiple blocks of statements and statements will execute
according to the condition.
Syntax
if (condition)
{
statements;
}
else if(condition)
{
statement;
}
else
{
statements;
}
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Example of if-else-if statement.
#include<stdio.h>
#include<conio.h>
void main( )
{
int a,b;
clrscr();
scanf("%d",&a);
scanf("%d",&b);
if(a>b)
{
printf("a is big");
}
else if(b>a)
{
printf(" b is big");
}
else
{
printf(" a is equal to b ");
}
getch();
}
In this example if a is greater than b then first block is executed and if b>a
then second block will execute else if none of the above conditions are true
then else part will execute. If –else-if is faster than multiple if block because
in this if first block is executed then all the other blocks are ignored by the
compiler.
Nested if
We can write if statement within the scope of another if or else block, it is
known as nested if.
Syntax of nested if:
if (condition)
{
if (condition)
{
do this;
}
else
{
do this;

and this;
}
}
else
{
do this;
}
In this syntax if condition 1 is true then compiler check the condition 2
and if condition 2 is also true then it will execute the statements written
in inner if block.
Example of nested if.
#include<stdio.h>
#include<conio.h>
void main( )
{
int a,b,c;
clrscr();
scanf("%d",&a);
scanf("%d",&b);
printf("enter the value of c");
scanf("%d",&c);
if(a>b)
{
if(a>c)
{
printf("a is big");
}
}
if(b>a)
{
if(b>c)
{
printf("b is big");
}
}
if(c>a)
{
if(c>b)
{
printf("c is big");
}
}
getch(); }
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#include<stdio.h>
#include<conio.h>
void main( )
{
int a,b,c;
clrscr();
scanf("%d",&a);
scanf("%d",&b);
scanf("%d",&c);
if(a>b)
{
if(a>c)
{
printf("a is big");
}
else
{
printf(“c is big”);
}
}
else
{
if(b>c)
{
printf("b is big");
}
else
{
printf(“c is big”);
}
} }
Conditional operator or ternary operator
The conditional operator is sometimes called ternary operator since they
take three arguments. These are the replacement for if else statements.
expression 1 ? expression 2 : expression 3
If expression 1 is true then the value returned will be expression 2
otherwise the value returned will be expression 3.

#include<stdio.h>
#include<conio.h>
void main( )
{
int a,b;
clrscr();
scanf("%d",&a);
scanf("%d",&b);
(a>b)?printf("a is big"):printf(" b is big");
getch();
}
Nested ternary operators.
#include<stdio.h>
#include<conio.h>
void main( )
{
int a,b,c;
clrscr();
scanf("%d",&a);
scanf("%d",&b);
scanf("%d",&c);
(a>b&&a>c)?printf("a is big"):(b>c)? printf(" b is big"):printf(“c is big”);
getch();
}
Switch statement
When we have multiple if statements then we can use switch case
statement. The variable used in switch is known as switch variable. The
variable in the switch statement can be of int or char type only. The switch
statement can also contain the default statements that will be executed if
none of the case is executed, default is optional.
syntax of Switch
switch (expression)
{
case 1:
...block of statements1...
break;
case 2:
...block of statements2...
break;
-----------------

-----------------
-----------------
default:
...block of statements for default..
break;
}
Program using if else if statements.
#include<stdio.h>
#include<conio.h>
void main( )
{
char c;
clrscr();
scanf("%c",&c);
if(c==’r’)
{
printf("colour is red");
}
else if(c==’b’)
{
printf("colour is blue");
}
else if(c==’g’)
{
printf("colour is green");
}
else
{
printf("colour is white");
}
}
Program using switch case statement.
#include<stdio.h>
#include<conio.h>
void main( )
{
char c;
clrscr();
scanf("%c",&c);
switch(c)
{
case ‘r’:

break;
case ‘b’:
printf("colour is blue");
break;
case ‘g’:
printf("colour is green");
break;
default:
}
}
Applications of switch:
1) It makes program easy to read and understand.
2) It is the replacement of multiple if statements.
3) Whole switch block is act like a single block.
Limitations of switch:
1) We can only use int and char type data.
2) We can not write relational operators in case.
Like case > 10 is wrong.
Write an algorithm and program to input two numbers if choice a
add it if choice s subtract it if choice d divide it otherwise give a
message wrong key pressed. Algorithm:-
Step 1: START
Step 2: DECLARE ch,a,b,c
Step 3: PRINT “Enter your choice”
Step 4: INPUT ch
Step 5: PRINT “Enter two numbers”
Step 6: INPUT a,b
Step 7: if(ch==’a’) then GOTO STEP 8 else GOTO STEP 9
Step 8: c=a+b PRINT c GOTO STEP 14
Step 9: If(ch==’s’) then GOTO STEP 10 ELSE GOTO STEP 11
Step 10: c=a-b PRINT c GOTO STEP 14
Step 11: if(ch==’d’) then GOTO STEP 12 else GOTO STEP 13
Step 12: c=a/b PRINT c GOTO STEP 14
Step 13: PRINT “wrong key pressed”
Step 14: STOP
Program
#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,c;
char ch;
printf(“enter two numbers”);
printf(“enter any character”);

fflush(stdin);
scanf(“%c”,&ch);
switch(ch)
{
case ‘a’:
c=a+b;
printf(“naddition=%d”,c);
break;
case ‘s’:
c=a-b;
printf(“nsubtraction=%d”,c);
break;
case ‘d’:
c=a/b;
printf(“ndivision=%d”,c);
break;
default:
printf(“nwrong key pressed”);
}
getch();
}
* fflush(stdin); is used to clear the buffer. It is always better to use this
function before entering character.
Important Questions [Short]
1. What are control statements?
2. Write syntax of if-else-if
3. Write difference between if and if-else.
4. Define ternary operators.
5. What is the use of default statement in switch?
Important Question [Long]
1. Explain switch case statement with example.
2. Explain working of nested if statements.
3. Write syntax of various control statements used in ‘C’.

Chapter 6
LOOPING AND BRANCHING STATEMENTS
Loops are used to execute statement or block of statements more than once.
In other words, Loop is defined as continuity. In simple language, it means
to do a particular task again and again till a particular condition is true or
satisfied.
For example
A person is given a task to go upstairs or downstairs for five no. of times
continuously. These processes of going up and down again and again are
known as loop. In a simple way we can say that a particular work or job is
done repeatedly.
Use of loops in programming is to calculate the result or percentage of
100,000 students of Punjab school education board. In this case, we have to
calculate the percentage of each student individually. To do this, we have to
apply the same formula again and again for each student. This process is
very time consuming, so to save memory space as well as time, loop is used
in the database. We can apply formula with the help of loop in one single
line according given condition.
Thus a loop is a part of program through which the control moves several
times during the execution of the program. The part which is executed again
and again is known as body of the loop. During the execution of loop,
whenever control falls to end of the body of the loop, it again jumps to the
starting point of body of the loop. This continues till a condition is satisfied
and control comes out of the loop if the condition is not satisfied.
In 'C' we have three types of loops. These are known as:
1. While
2. Do while
3. For
In mostly every loop we have to identify 3 main parts of the loop.
a) initialization: Starting point of the loop
b) Condition:- Ending point of the loop
c) Increment/Decrement:- How will we reach from starting to
end point of the loop.
1. While :- It executes the block of statements till the value of the
conditional expression is true. In while if condition is true, then the body of
the loop is executed. After execution of the body [contain statements and
increment/decrement part], the test condition is again tested and if it is
true, the body is executed again. This process is repeated till the test is
true.
Syntax: -
While (expression)
{
Statement a;
Statement b;

Increment/decrement;
}
There will be no semicolon at the end of the line containing the keyword
while in while loop.
1) Write an algorithm and draw flowchart
to print “HELLO” 10 times.
Algorithm
Step 1: START
Step 2: DECLARE A
Step 3: A=1
Step 4: IF A<=10 GOTO STEP 5
ELSE GOTO STEP 7
Step 5: PRINT “HELLO”
Step 6: A=A+1 GOTO STEP 4
Step 7: STOP
Or
Algorithm
Step 1: START
Step 2: DECLARE A
Step 3: A=1
Step 4: Repeat while A<=10
PRINT “HELLO”
A=A+1
End loop
Step 7: STOP
Write A Program To Print 1 To 10 Series.
#include<stdio.h>
#include<conio.h>
void main()
{
int a=1;
clrscr();
while(a<=10)
{
printf(“n%d”,a);
a++;
}
getch();
}
a=1 is the starting point of the loop and condition written in while is the
end point a++ is the increment. This represents that loop starts from 1
ends at 10 and increment 1. So output will be 1 2 3 4 5 6 7 8 9 10,
N0
yes
Declare
A
IF
A<=10
PRINT”HELLO”
STOP
START
A=1
A=A+1

similarly in following program loop starts from 2 ends at 100 with 2
increment.
Write A Program To Print Series 2,4,8,10-----100
#include<stdio.h>
#include<conio.h>
void main()
{
int a=2;
clrscr();
while(a<=100)
{
printf(“%d”,a);
a=a*2;
}
getch();
}
Loops are also very helpful if we want to multiply , add or count number
from the continue list like 2 4 6 8 10 12 14 16 18 20 to add numbers we
use s=s+a where s is used for sum and a is the variable of the loop at start
value of s should be initilized with 0 as in the following example value of s
in the beging of the loop is 0 after one iteration of the loop value of s=s+1
means s=0+1 this make s=1 and after second itration s=1+2 so s is 3
similar after third itration s=3+3 (6) after fourth s=6+4 (10) this is
executed 10 times. In the end value of s=1+2+3+4+5+6+7+8+9+10=55.
Similarly if we want to count numbers we use c=c+1 and for multiply
m=m*a.
Write a program to find sum of 1 to 10 numbers
#include<stdio.h>
#include<conio.h>
void main()
{
int a=1,s=0;
clrscr();
while(a<=10)
{
s=s+a;
a++;
}
printf(“%d”,s);
getch();
}

2. DO-WHILE: - It checks the condition after executing the statements so it
executes the statements at least once even if the expression is false.
Condition is checked at the end of the do while loop. Mostly this loop is
used for software testing (Means whether the condition is true or false, loop
will be execute once)
Syntax
do
{
Statement a;
Statement b;
Increment/decrement;
}
while (expression);
There will be no semicolon at the end of the line containing the keyword
do, But we need to place semicolon at the end of keyword while.
1) Write an algorithm to print “hello” n times.
Algorithm
Step 1: START
Step 2: DECLARE i,num
Step 3: PRINT “Enter the ending point number”
Step 4: INPUT num
Step 5: i=1
Step 6: PRINT “hello”
Step 7: i=i+1
Step 8: if(i<=num) then GOTO STEP 6 else GOTO STEP 9
Step 9: STOP
Write A Program To Print hello N times
#include<stdio.h>
#include<conio.h>
void main()
{
int i =1 ,num;
clrscr();
printf(“enter number”);
scanf(“%d”,&num);
do
{
printf(“hello”);
i++;
}
while(i<=num);
getch();
}
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Difference between do-while loop and while loop
In both the cases the condition is checked. In case of while, condition is
checked before the execution of the statements but in case of do-while,
statements are executed at least once whether the condition is true or false
i.e. condition is checked at the end of the do-while block.
a=11;
while(a<=10)
{
printf(“%d”,a);
a++;
}
a=11;
do
{
printf(“%d”,a);
a++;
} while(a<=10);
Output: [BLANK SCREEN] Output: 11
3. FOR: - In for loop the initialization, condition and increment or
decrement can be done in one line. It executes the statements till the
condition is true. Mostly this loop is used in complex programming.
Syntax
for (initialization; condition; increment/decrement)
{
Statement;
Statement;
}
1) First initialize the variable.
2) After initialization, condition is checked. If condition is true then
statement is executed.
3) After that increment or decrement the variable according to
condition.
Write a program to find sum of 1 to 10 numbers
#include<stdio.h>
#include<conio.h>
void main()
{
int a,s=0;
clrscr();
for(a=1;a<=10;a=a+1)
{
s=s+a;
}
printf(“%d”,s);
getch();
}

Write a program to print factors of a number
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,c=0;
clrscr();
printf("enter a no");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
if(n%i==0)
{
printf(" %d",i);
}
}
getch();
}
Write a program to count factors of a number
To count factors we use formula c=c+1 the value of c is incremented
every time we find a value of i that divide the number n. In the end of
the loop the value of C is equal to the total factors of n.
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,c=0;
clrscr();
scanf("%d",&n);
for(i=1;i<=n;i++)
{
if(n%i==0)
{
c=c+1;
}
}
printf("count= %d",c);
getch();
}

Write a program to print number is prime or not.
*Prime numbers are only divided by 1 or itself like 7, 11, 13, 17 etc.
This program is same as last one only we add a condition in the end that
if no of factors are 2 then no is prime else not.
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,c=0;
clrscr();
scanf("%d",&n);
for(i=1;i<=n;i++)
{
if(n%i==0)
{
c=c+1;
}
}
if(c==2)
printf("number is prime");
else
printf("number is not prime");
getch();
}
Write a program to print sum of digits of a number.
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,s=0;
clrscr();
scanf("%d",&n); //let n=1234
while(n>0)
{
i=n%10; //4 3 2 1
s=s+i; //0+4=4 4+3=7 7+2=9 9+1=10
n=n/10; //123 12 1 0
}
printf("sum of digits =%d",s); //so s=10
getch();
}
Write a program to print reverse of a number.

#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,s=0;
clrscr();
scanf("%d",&n); // let n=1234
while(n>0)
{
i=n%10; //i=4 3 2 1
s=s*10+i;//s=0*10+4=44*10+3=4343*10+2=432432*10+1=432
n=n/10;
}
printf("reverse of a number =%d",s);
getch();
}
Write a program to print no is Armstrong or not.
*153 is an Armstrong number because
1*1*1 = 1
5*5*5 = 125
3*3*3 = 27
Total 157
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,s=0,m;
clrscr();
scanf("%d",&n);
m=n;
while(n>0)
{
i=n%10;
s=s+i*i*i;
n=n/10;
}
if(s==m)
printf("number is Armstrong”);
else
printf("number is not Armstrong”);
getch();
}

1. NESTED LOOP: -Nested loop means nesting or loops means within
loop. In nested loop the first loop is called outer loop & second loop is
called inner loop. In this the condition of outer loopis true then the
condition of inner loop is checked. If it is true then inner loop will
execute. The inner loop would act as a part of the body for the outer
loop. Therefore, execution of inner loop will depend on the execution of
the outer loop.
Syntax
for (initialization; condition; increment/decrement) //outer
Loop
{
for (initialization; condition; increment/decrement)
// Inner
loop
{
Statement;
}
}
Why we use nested loops:- If we want to find sum of 5 subjects of a
student we use single loop and if we want to find sum of 5 students in 5
subjects each then we need to execute the loop 5 times so that we can find
sum of 5 students for this we need nested loops. E.g
For(stu=1;stu<=5;stu=stu+1)
{
for(sub=1;sub=1;sub=sub+1)
{
statements;
}
}
If the condition of outer loop is true then control will goto the inner loop
and if the condition of inner loop is true then executes the statement. If the
condition of outer loop is false the control doesn’t go into in the inner loop.
Write a program to print :-
12345
12345
12345
12345
12345
#include<stdio.h>
#include<conio.h>
void main()
{
int i,j;
clrscr();
for(i=1;i<=5;i++)

{
for(j=1;j<=5;j++)
{
printf(“%d”,j);
}
printf(“n”);
}
getch(); }
In above program we have used nested loop. Ist loop is outer loop and 2nd
loop is inner loop. If the outer loop is true then control goes to the inner
loop otherwise exit the control in outer loop. In simple meaning outer loop
act as no of rows and inner as no of column.
Write a program to print 1
12
123
1234
12345
#include<stdio.h>
#include<conio.h>
void main()
{
int i,j;
clrscr();
for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++)
{
printf(“%d”,j);
}
printf(“n”);
}
getch();
}
22
333
4444
55555
#include<stdio.h>
#include<conio.h>
void main()
{
int i,j;
clrscr();

for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++)
{
printf(“%d”,i);
}
printf(“n”);
}
getch();
}
99
999
9999
#include<stdio.h>
#include<conio.h>
void main()
{
int i,j;
clrscr();
for(i=1;i<=5;i++)
{
for(j=1;j<=i;j++)
{
printf(“9”);
}
printf(“n”);
}
getch();
}
Write a program to print 1 to 1000 palindrome numbers.
#include<stdio.h>
#include<conio.h>
void main()
{
int n,i,s=0,m;
clrscr();
for(m=1;m<=1000;m++)
{
n=m;
s=0;
while(n>0)
{
i=n%10;

s=s*10+i;
n=n/10;
}
if(s==m)
printf(" %d",s);
}
getch();
}
Branching Statements
There are another kind of control statements that can change the execution
of loop or execution of the program. Branching statements are further
divided into three types.
a. Break
b. Continue
c. goto
Break: - Break statement is used to exit from the loop or switch statement.
Whenever break statement is encountered the rest of the statements inside
the loop are ignored and the control go to the next statements after the
loop. It can also be used with a while , a do while , a for or a switch
statement.
EXAMPLE BREAK STAEMENT
#include<stdio.h>
#include<conio.h>
void main()
{
int i;
clrscr();
for(i=1;i<=10;i++)
{
if(i==5)
{
break;
}
printf("n% d",i);
}
getch();
}
output

1
2
3
4
*exit function:- It terminates the whole program instead of loop..
Continue: -The continue statement is used to skip the remaining
statements of the body of the loop where it defined, it does not terminate
the loop but the control is transferred to the start of the next loop iteration.
Continue statement is used to only break the current iteration. After
continue statement the control returns to the top of the loop test
conditions.
Example continue statement
#include<stdio.h>
#include<conio.h>
void main()
{
int i;
clrcsr();
for(i=1;i<=10;i++)
{
if(i==5)
{
continue;
}
printf(“ %d ”,i);
}
getch();
}
Output: 1 2 3 4 6 7 8 9 10
Goto: - The goto statement is control statement that causes the control to
jump to a different location in the program with or without checking any
condition . It is always used with the label. It increase the readable
complexity of the program so programmers avoid to use this. The goto
statement can only be used within the body of a function definition.
There are two types of goto:-
1) Unconditional jump
2) Conditional jump

1. Unconditional Jump: In this control is transferred from one
statement to another without any condition.
EXAMPLE Unconditional GOTO STATEMENT
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
printf(“none”);
printf(“nTwo”);
printf(“nThree”);
goto abc;
printf(“Four”);
printf(“Five”);
printf(“nSix”);
abc:
printf(“nSevan”);
printf(“nEight”);
getch();
}
Output
One
Two
Three
Seven
Eight
2. Conditional Jump: In this control is transferred from one
statement to another according to the condition.
EXAMPLE conditional GOTO STATEMENT
#include<stdio.h>
#include<conio.h>
void main()
{
int a;
Abc:
printf(“Enter no greater than 10”);
scanf(“%d”,&a);
if(a<=10)
goto Abc;
printf(“You enter number greater than 10”);
getch();
}
in this program control goes back to Abc label until user not enter number
greater than 10.

1. What do you mean by loop?
2. What are the limitations of goto statement?
3. Write advantages of for loop over while and do-while.
1. Explain various types of loops in 'C' language .
2. Write difference between break and continue.
3. Write difference between while and do-while.
4. What are various jump statements in 'C' language .
CJ SOFTECH Walia Enclave Opp Punjabi Univ PatialCJ SOFTECH Walia Enclave Opp Punjabi Univ PatialCJ SOFTECH Walia Enclave Opp Punjabi Univ PatialCJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.a.a.a.

Chapter 7
ARRAYS AND STRINGS
Arrays are group of similar data types. It’s used to store a large amount of
data. The array elements are stored in contiguous memory locations. In
other words, if an array is declared to be of an int type, it can’t contain
elements that are not of int type.
How to declare an Array:
DataType variablename[size]
Example:- int ary[5];
10 20 30 40 50
ary[0] ary[1] ary[2] ary[3] ary[4]
In the above program ary is variable name which hold the 5 elements which
have a same name, same data type but with different memory locations. As
the memory is allocated sequentially so that data can be easily accessed by
increment or decrement by single variable. Arrays always start with index
value zero.
Advantages of arrays
1. Array is the simplest data structure.
2. It is easy to create.
3. We can use one name for similar identifier.
4. Arrays use reference type so we need not to use return statement.
Limitations
1. Array may require large amount of contiguous memory, which is not
available sometimes.
2.Bound checking is not done by 'C' compiler. Means in ary[5] the index
value should be between 0 to 4 but if we write ary[7],ary[34] etc compiler
does not show any error and display garbage value.
3. Overflow condition may occur in array if we want to store more values
then its size.
ARRAY TYPES
Array is two types
1) One dimensional array
2) Multidimensional array
1) One dimension array:- A list of items have only one subscript and
such a list is called one dimensional array.
Declaration of an array.
int a[5];
In the above example we defined an array a [5]. Here a is a variable
name. Data type of a is integer and 5 is the size of an array. Size is always
written in subscript []. This means that it can store only five elements.
Index of a is start from 0 to 4.
Initialization of an array:- we can also assign values to an array when
we declare it.
int a[]={1,2,3,4,5};

compiler automatically sets the size of the array like in this case size of a is
5 and it requires 10bytes of memory[2 for each int]
int a[10]={1,2,3,4,5,6,7,8,9,10};
In this we assign values to the ten elements of a. We can access
array elements with its index, for example, if we want to print 5th
element
from the list we use a[4].
Write a program to print five elements of an array.
#include<stdio.h>
#include<conio.h>
void main()
{
int a[]={1,2,3,4,5};
clrscr();
printf(“%d”,a[0]);
getch();
}
In this program 1 is store at location 0,2 at location 1 similarly others.
When we print a[0] it will display 1.
Write a program to input and print five elements using array.
**it is always helpful to use loop in array
#include<stdio.h>
#include<conio.h>
void main()
{
int a[5],i;
clrscr();
for(i=0;i<=4;i++) /*it will execute scanf statement 5 times and
value in array*/
{
printf(“enter array element=”);
scanf(“%d”,&a[i]);
}
for(i=0;i<=4;i++)
{
printf(“ %d”,a[i]);
}
getch();
}
2)Multidimensional Array: - Array in 'C' can have more than one
dimension. An array with two dimensions or more is known as

multidimensional array. Multidimensional array can be of 2-
Dimensional , 3-Dimensional, 4-Dimensional and so on.
int a[2][2]; in this a is 2-D array
int a[2][3][2]; in this a is 3-D array
int a[2][4][4][2]; in this a is 4-D array
2-D Array: - 2-Dimensional array is also known as matrix because in this
elements are stored in the form of rows and columns. A[4][5] means A is an
array with 4 rows and 5 columns. We can store 20 elements in A[4][5] array
and size of A is 40bytes.
A[0][0] A[0][1] A[0][2] A[0][3] A[0][4]
A[1][0] A[1][1] A[1][2] A[1][3] A[1][4]
A[2][0] A[2][1] A[2][2] A[2][3] A[2][4]
A[3][0] A[3][1] A[3][2] A[3][3] A[3][4]
Nested loops are used to input and print data from 2-D array. Outer loop is
used to represent rows and inner is used to represent column.
Write a program to print 2*3array matrix.
#include<stdio.h>
#include<conio.h>
void main()
{
int a[2][3],i,j;
clrscr();
printf(“enter array matrix”);
for(i=0;i<2;i++)
{
for(j=0;j<3;j++)
{
scanf(“%d”,&a[i][j]);
}
}
for(i=0;i<2;i++)
{
for(j=0;j<3;j++)
{
printf(“ %d”,a[i][j]);
}
printf(“n”);
}
getch();
}
Write a program to add two matrices.
#include<stdio.h>
#include<conio.h>
void main()
{

int a[5][5] , b[5][5],c[5][5],i,j;
clrscr();
printf(“enter 1st matrix”);
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
}
}
printf(“enter 2nd matrix”);
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
scanf(“%d”,&b[i][j]);
}
}
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
c[i][j]=a[i][j]+b[i][j];
printf(“ %d”,c[i][j]);
}
printf(“n”);
}
getch();
}
a b c
Write a program to
multiply two
matrices.
#include<stdio.h>
#include<conio.h>
void main()
{
int a[5][5] , b[5][5],c[5][5],i,j,k;
clrscr();
printf(“enter 1st matrix”);
for(i=0;i<=4;i++)
1 1 1 1 1
1 1 1 1 1
1 1 1 1 1
1 1 1 1 1
1 1 1 1 1
2 3 4 5 6
2 3 4 5 6
2 3 4 5 6
2 3 4 5 6
2 3 4 5 6
1 2 3 4 5
1 2 3 4 5
1 2 3 4 5
1 2 3 4 5
1 2 3 4 5

{
for(j=0;j<=4;j++)
{
}
}
printf(“enter 2nd matrix”);
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
scanf(“%d”,&b[i][j]);
}
}
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
c[i][j]=0;
for(k=0;k<=4;k++)
{
c[i][j]=c[i][j]+a[i][k]*b[k][j];
}
}
}
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
printf(“%d”,c[i][j]);
}
printf(“n”);
}
getch(); }
Write a program to print transpose of matrix.
Transpose means converting the rows into column;
#include<stdio.h>
#include<conio.h>
void main()
{
int a[5][5],i,j;
clrscr();
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)

{
}
}
for(i=0;i<=4;i++)
{
for(j=0;j<=4;j++)
{
printf(“ %d”,a[j][i]);
}
printf(“n”);
}
getch();
}
A B
3-Dimensonal array:- eg int A[4][5][3]. In this
we can store total 4*5*3=60 elements and size
of A is 120 bytes.
Write a program of 3-D Array.
#include<stdio.h>
#include<conio.h>
void main()
{
int a[3][5][4],i,j,k;
clrscr();
for(i=0;i<=2;i++)
{
for(j=0;j<=4;j++)
{
for(k=0;k<=3;k++)
{
scanf(“%d”,&a[i][j][k]);
}
}
}
for(i=0;i<=2;i++)
{
for(j=0;j<=4;j++)
{
for(k=0;k<=3;k++)
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
1 5 9 13 17
2 6 10 14 18
3 7 11 15 19
4 8 12 16 20

{
printf(“%d”,a[j][i][k]);
}
}
}
getch();
}
String
C language does not provide any data type in which we can represent
collection of character. So if we want to do this we use character array that
is called string. As we can store more than one element in integer or float
array, similarly we can store more than one character in character array.
Group of characters is also known as String.
A string is a one dimensional array of characters terminated by a NULL(‘0’).
For example,
char name[20]={‘P’,’R’,’A’,’T’,’H’,’A’,’M’};
or
char name[20]={“PRATHAM”};
The size of name is 20 bytes(1 byte for 1 char) and we use only first three
bytes to store “PRATHAM” after this we have 13 bytes left that contain
garbage value. But when we print it, it display first three characters only
because compiler place NULL also represented as ‘0’ at the end of the
string, so when compiler print the string it print up to NULL character. We
can input and print string using %s format specifier in scanf and printf
functions. We can also use gets to input a string and puts to print a string.
Write a program to input and print a string.
Output: [if we use scanf]
Enter name Charanjiv Singh
Name=Charanjiv
Output:if we use gets]
Enter name Charanjiv Singh
Name=Charanjiv Singh
2-D Character Array
we can use two-dimensional char array to create an array of strings.
#include<stdio.h>
#include<conio.h>
void main()
{
char ch[20];
clrscr();
printf("Enter name ");
scanf("%s",&ch); // or we can use gets(ch);
printf("Name=%s",ch);
getch();
}

For example; char names[10][20];
it can be used to represent ten different strings
For example,
char days[7][10]={“Monday”, “Tuesday”............”Sunday”};
can be used to store name of days.
Here 7 means we pass 7 strings and 10 means each string consist 10
charcaters.
#include<stdio.h>
#include<conio.h>
void main()
{
int i;
char name[12][10]={"Jan", "feb", ",mar", "apr", "may", "jun",
"jul", "aug", "sep", "oct", "nov", "dec"};
int days[12]={31,28,31,30,31,30,31,31,30,31,30,31};
clrscr();
for(i=0;i<12;i++)
printf(" %s has %d days:",name[i],days[i]);
getch();
}
String library functions are the functions, which are used regularly and
stored in library file and whenever these functions are needed , you need to
include the required header file in your program like as,
#include<string.h>
There are 7 inbuilt functions to perform different operations on strings.
1.. strlen: This function is used to count the characters in a
string. It calculates the length of the string.
Syntax:
strlen(array variable);
#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
char s1[20];
int i;
clrscr();
printf(“Enter string “);
scanf(“%s”,&s1);
i=strlen(s1);
printf(“Length=%d”,i);
getch();
}

2. strcpy: This function copies the contents of one string into
another string.
Syntax
strcpy(target,source);
#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
char s1[20],s2[20];
clrscr();
strcpy(s2,s1);
printf(“string =%s ”,s2);
getch();
}
3. strcat: This function is used to concatenate the source string
at the end of the target string.
Syntax
strcat(target,sourcetoadd);
#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
char s1[20],s2[20];
int i;
clrscr();
strcat(s2,s1);
printf(“ concatenated string =%s ”,s2);
getch();
}
4. strcmp: This function compares two strings to find out whether
they are same or different. The two strings are compared character by
character until there is a mismatch or end of the string. This function
returns 0 if both the strings are identical.
Syntax
Strcmp(string1,string2);

#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
char s1[20],s2[20];
int i;
clrscr();
i=strcmp(s2,s1);
if(i==0)
printf(“ Both strings are same”);
else
printf(“ Strings are not same”);
getch();
}
5. strrev() : - String reverse function is used to reverse the
string. This function also contain a single argument
6. strupr() : - String upper case is used to convert the string in
to upper case or in capital letter. This function contains single
argument.
7. strlwr() : - String lower case is used to convert the string into
lower case or in small letter. This function contains single argument.
atoi()[define in stdlib header file: This function comes under <stdlib.h>
header file. This function convert numeric string into integer
Syntax
int atoi(string);
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void main()
{
char s1[20];
int i;
clrscr();
i=atoi(s1);
printf(“ i=%d”,i);
getch();
}
String can also be accessed as array like we can create programs without
using string functions.

WAP to print length of string without using inbuilt function.
#include<stdio.h>
#include<conio.h>
void main()
{
char s1[20];
int i;
clrscr();
i=0;
while(s1[i]!=NULL)
{
i++;
}
printf(“ length of string =%d ”,i);
getch();
}
*Similarly we can also create other string functions.
1. Define array.
2. How we can declare and initialize an array?
3. Define 2D array.
4. Define string.
5. Explain subscripted elements.
1. Explain memory representation of array.
2. Explain String with example.
3. Explain inbuilt functions of string.

Chapter 8
FUNCTIONS
Functions are the blocks of C programs which perform the specifc task.
Functions are used to divide the long program into sub program. In general,
a function is a block of code that performs one or more actions. Functions
are called by other functions. A program in the C language consists of
several functions. One such function we use is the main () function. Every
function has a name. The name of the function ends with a pair of
parenthesis. This parenthesis may or may not contain any thing. Whatever is
inside the parenthesis is known as the arguments of the function.
While defining function you must know these things: -
1. Function name.
2. Function return type (if there is no return then use void)
3. Function argument( if there is no argument here also use void).
Syntax to define a function:
<Return type> <function name>(<arguments>);
Example: -
void show();
Why we use function: -
1. Functions are used to find the errors in the program.
2. Functions are used for reusability.
3. It decreases the cost of the software.
4. It increases the efficiency.
5. It makes the programming simple.
6. It reduces the complexity of the program.
Types of Functions
There are two types of functions. First are known as built in functions and
second are the user defined functions.
1. Built in functions: - Built in functions are those functions,
which are provided to us by the programming language. But before
using these functions we have to include some header files like,
<stdio.h> which are provided to us by the various input output
related functions like printf() and scanf() function. Others are string
handling functions, mathematical functions which are stored in
<string.h> and <math.h> header file respectively.
Math Functions
Some examples of Math functions
Basic Math functions are sqrt() ,pow(), cos(), tan() and sin() etc.
1. sqrt ():- This function returns the square root of a number.
This function accepts a single argument. As shown in the syntax and
example given below: -
The syntax for the sqrt() function is:-
# include <math.h>
int sqrt(int h);

Here, the sqrt() function returns the non-negative square root of h in
the integer data type. This function returns an error if h is negative.
Example of sqrt() function:-
#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
int n;
clrscr();
printf(“enter any number”);
scanf(“%d”,&n);
printf(“square root of n=%d”,sqrt(n));
getch();
}
2. pow():- This function returns the power of a number. This
function accepts two arguments ,first is the number and the second is
its power. As shown in the syntax and example: -
Syntax: -
#include <math.h>
int pow(int x, int y);
Here, the value of the int variable x is raised to the power of y. The
pow() function returns the result in the int data type.
Example of pow() function:-
#include<stdio.h>
#include<conio..h>
#include<math.h>
void main()
{
int n,p;
clrscr();
scanf(“%d”.&n);
printf(“enter their power”);
scanf(“%d”,&p);
printf(“power of n=%d”,pow(n,p));
getch();
}
String handling functions
We also use string-handling functions, which are used for string
manipulations. These functions are like strcpy(), strcat(),
strupr(),strlen(), strrev(), strlwr() and strcmp() etc.

2. User defined Functions: - These functions are defined by the
user are according to their requirement, known as User define
functions. User defined functions have four types: -
a) Without Return Without Arguments
b) Without Return with Arguments
c) With Return Without Argument
d) With Return With Argument
For creating user defined functions we have to follow three basic
steps. These are given below: -
a) Function Declaration / Function Prototyping
b) Function Definition
c) Function Calling
a) Function declaration: - Function declaration is also known as
function prototyping. Before using functions in your program it must be
declared and defined. Function declaration or prototyping tells the
compiler that this function is used later in the programming. It also tells
the compiler their name, return type, and arguments of the function. No
function can be called from any other function that hasn't first been
declared. The declaration of a function is also called function prototype.A
prototype always ends with a semicolon (;).Function is declared same as
we declare variables before using them.
b) Function Definition: - In function definition we can define the body
of the function. It means we can write the number of statements inside
the opening and closing brace of the function, which are executed when
the function is called by some other function. A function definition must
match (their name, return type and parameter list) with its declaration.
The definition tells the compiler how the function works.
c) Function calling: - Function calling means to execute the function.
After declaration and definition of the function we can call the function for
their execution. When you call a function, execution begins with the first
statement to last statement of the function. Functions can also call other
functions and can even call themselves but mostly the main function call
the sub function.
Categories of user defined functions:
1. Without Return Without Argument: - This is the first type of user
define function and also known as no return no argument. No return
means that function start with ‘void’ keyword. It tells the compiler that
the function cannot return any value. No arguments mean we cannot
pass anything from the calling function to called function. It means we
can leave the parentheses blank. In C, the declaration of the show ()
function can be something like this:
Void show();
We can also write it as;

void show(void);
Note that the keyword ‘void’ is used in the declaration to indicate to the
compiler that no argument is passed to the function. The compiler will
produce an error message if an argument is passed to show () function later
in a program when this function is called.
Example1.WAP to add and subtract two numbers using function with
no return no argument.
As show in the Example: -
#include<stdio.h>
#include<conio.h>
void sum(); //Function declaration
void sub();
void main()
{
clrscr();
sum(); //Function calling
sub();
getch();
}
void sum() ///function Definition
{
int a,b,c;
printf(“enter first number”);
scanf(“%d”,&a);
printf(“enter second number”);
scanf(“%d”,&b);
c=a+b;
printf(“sum=%d”,c);
}
void sub() ///function Definition
{
int a,b,c;
printf(“enter first number”);
scanf(“%d”,&a);
printf(“enter second number”);
scanf(“%d”,&b);
c=a-b;
printf(“sub=%d”,c);
}
2. Without Return with argument:- This is the second type of user
define functions. This function starts with void keyword, which tells the
compiler that function hasn’t any return type. It can’t return any thing to
its calling program. But with argument means we must pass information
to the calling function. In this we should declare variables inside the
parentheses we cannot leave the parentheses blank. The argument of a

function is placed between the parentheses after the function name. If a
function has more than one argument then arguments must be separated
by commas. We can declare a function with a fixed number of arguments,
but then you need to specify the data type of each argument.
Arguments are of two types: -
1) Formal arguments
2) Actual arguments
1. Formal Arguments:-Formal arguments are those arguments which
are declared at function declaration and function definition time. For
example:
void sum(int a,int b);
Here a and b are the formal arguments which are passed into the
sum function.
2. Actual arguments:-Actual arguments are those arguments which are
passed to function at calling time. For example
sum(3,5);
Here 3 and 5 are our actual arguments which are passed into the
sum() function.
As Shown in the example:-
Example 2. WAP to find the square and cube of a number using
function with argument.
#include<stdio.h>
#include<conio.h>
void sqr(int n); //function declaration
void cube(int n);
void main()
{
int a;
clrscr();
scanf(“%d”,&a);
sqr(a); //calling the function
cube(a); //here a is actual parameter
getch();
}
void sqr(int n)
{
int m;
m=n*n;
printf(“n the square=%d”,m);
}
void cube(int n)
{
int m;
m=n*n*n;

printf(“n the cube=%d”,m);
}
Local variables: - Local variables are those variables, which are declared
inside a block or function. These variables are accessible only within the
block and are passed as argument into the function or declared inside the
function. These are also known as function level variable because they are
accessible only within the function.
Global variables: - Global variables are those variables, which are declared
outside the block or function. These are known as global variables. Which is
accessible by each block of the program.
3. With return without Argument: - Return type functions are
those functions, which return a value to the calling function. These
functions start with a specific data type in place of void keyword. These
type of functions use return keyword to send the data back to the
calling function.
As shown in the example:-
Example 3. WAP to find the factorial of a given number using
function with return type.
#include<stdio.h>
#include<conio.h>
int fact(); //Function declaration
void main()
{
int f;
clrscr();
f=fact(); //calling the function
printf(“n the fatorial=%d”,f);
getch();
}
int fact() // Function definition
{
int a,b=1,n;
scanf(“%d”,&n);
for(a=1;a<=n;a++)
{
b=b*a;
}
return b;
}
4. With return with argument: - This function contains argument
and also return the value to its calling function, as show in the given
example :.

Example 4. WAP to reverse a number using function with
return and with argument.
#include<stdio.h>
#include<conio.h>
int reverse(int n); //Function declaration
void main()
{
int a,b;
clrscr();
printf(“please enter any number”);
scanf(“%d”,&a);
b=reverse(a); // Function calling
printf(“n Reverse of a number=%d”,b);
getch();
}
int reverse(int n) ///Function definition
{
int r,s=0;
while(n>0)
{
r=n%10;
s=s*10+r;
n=n/10;
}
return s; }
Recursive Functions
Recursive functions are those functions, which call itself again and again.
Normally function is called by the other function, but in recursive function it
call itself repeatedly. This process known as recursion, as shown in the
example below:
Example . WAP to find the factorial of a given number using
recursion.
#include<stdio.h>
#include<conio.h>
int fact(int n);
void main()
{
int n,f;
clrscr();
scanf(“%d”,&n);
f=fact(n);
printf(“factorial=%d”,f);
getch();

}
int fact(int n)
{
if(a==1)
{
return 1;
}
else
{
return n*fact(n-1);
}
}
Example:WAP to print the fibonacci series.
#include<stdio.h>
#include<conio.h>
int fibo(int a,int b);
void main()
{
clrscr();
fibo(0,1);
getch();
}
int fibo(int a,int b)
{
printf(“%d”,a);
if(a>100)
{
return 0;
}
fibo(b,a+b);
}
Call by Value
In C language by default, the arguments are passed to the function by
value. It means the actual arguments copy their value into the formal
arguments. In call by value, we can pass the value. If any change is done
into the formal arguments, it doesn’t affect the actual arguments because
both the arguments use the different memory location.
As show in the example:-

#include<stdio.h>
#include<conio.h>
void show(int a); //declaring the function (a is our formal
argument)
void main()
{
int x;
clrscr();
scanf(“%d”,&x);
show(x); //calling the function ( x is our actual arguments)
printf(“n now value of x=%d”,x);
getch();
}
void show(int a) // function definition ( a is our formal
argument)
{
a=a+1;
printf(“n the value of a=%d”,a);
}
Output
Enter any Number = 5
The value of a = 6
Now value of x = 5
Call by reference
In call by reference we can pass the address of a variable in place of value.
It means we can pass the address of actual argument to the formal
argument. If any change is done in to the formal arguments ,it also affects
the actual arguments, because the address of the actual arguments are
passed to the formal arguments .In call by reference, we can pass pointer
variable as formal arguments.
As show in the example:-
#include<stdio.h>
#include<conio.h>
void show(int *a); //declaring the function (a is our
formal argument)
void main()
{
int x;
clrscr();
scanf(“%d”,&x);
show(&x);///calling the function ( x is our actual
arguments)
printf(“n now value of x=%d”,x);
getch();

}
void show(int *a)// function definition ( a is our formal
argument)
{
*a=*a+1;
printf(“n the value of a=%d”,*a);
}
Output
Enter any Number = 5
The value of a = 6
Now value of x = 6
Passing array as argument into the function
Sometimes it's difficult to call a function that requires number of arguments.
One way around this is to store the variables into an array. So we can pass
an array as argument into the function. As shown in the example:
#include<stdio.h>
#include<conio.h>
void show(int a[]); //Parameter Array Type
void main()
{
int x[5],i;
clrscr();
for(i=0;i<5;i++)
{
scanf(“%d”,&x[i]);
}
show(x);
getch();
}
void show(int a[])
{
int i;
for(i=0;i<5;i++)
{
printf(“n%d”,a[i]);
}
}
Passing structure as argument into the function
We can also pass structure as an argument into the function same as any
other variable. As shown in the example:
#include<stdio.h>
#include<conio.h>
struct student
CJ SOFTECH Walia Enclave Opp Punjabi Univ PatialaCJ SOFTECH Walia Enclave Opp Punjabi Univ PatialaCJ SOFTECH Walia Enclave Opp Punjabi Univ PatialaCJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala....

{
char name[20];
int roll,marks;
};
void show(struct student);
void main()
{
struct student s;
clrscr();
printf("enter student name");
scanf("%s",&s.name);
printf("enter student roll number");
scanf("%d",&s.roll);
printf("enter student marks");
scanf("%d",&s.marks);
show(s);
getch();
}
void show(struct student s)
{
printf("nstudent name=%s",s.name);
printf("nstudent roll=%d",s.roll);
printf("nstudent marks=%d",s.marks);
}
Nested Function
Nested function means a function inside a function. But C does not allow
nested functions. But we can call one function into another function. It is
also known as nested function. As shown in the example:
#include<stdio.h>
#include<conio.h>
void sum(int a,int b);
void input(int a,int b);
void input(int a,int b)
{
sum(a,b);
}
void sum(int a,int b)
{
int c;
c=a+b;
printf(“the sum=%d”,c);
}
void main()
{
int x,y;
clrscr();

printf(“enter the value of x”);
scanf(“%d”,&x);
printf(“enter the value of y”);
scanf(“%d”,&y);
input(x,y);
getch();
}
Important Short Answer type questions
1. What are functions?
2. What are the advantages of functions?
3. What are arguments?
4. What do you mean by built in functions?
5. Write a note on user defined functions?
6. What is recursion?
7. What are the uses of functions?
8. What are the advantages and disadvantages of recursion?
Important Long Answer Type Questions
1. Write a note on user-defined functions. Why are they used?
2. What are the various types of functions supported by C? Give
examples for each type of the C functions.
3. What is the relationship between actual arguments and formal
arguments? Explain with example?
4. Explain recursion in C with an example?
5. Write a function to find the factorial of a number using with
return with argument.
6. Write a function to find the sum of n natural numbers using
recursion.
7. Write the difference between Function prototyping and Function
definition.
8. Write the two ways in which arguments can be passed to
function.
9. Write a program to pass an array as an argument into the
function.
10. Write a function to reverse a given integer using with return
with argument?
11. Write a program to display the first n terms of Fibonacci series
using recursion.

Chapter 9
STORAGE CLASSES
Storage classes tell us about three things.
1. Storage classes tell us about the memory. It means a variable
uses which type of memory. It uses RAM or any other memory (CPU
Memory).
2. Storage classes tells us about the scope of variable.The scope of
a variable is defined as the area of program in which it is accessible.
3. Storage classes tells us about the default value of the variable.
There are four types of storage classes.
1. Auto
2. Static
3. External
4. Register
1. Auto: - Auto means automatically. It is the default scope of variables
and they are declared with or without auto keyword, belong to auto
storage class. Auto variable are active in the block in which they are
declared. Block means statements inside the braces ({}).
The scope of auto variable is limited. It means they are local
variable. They can access within the block where they are
declared.
The auto storage class variable uses primary memory for storing
data. It means RAM.
The default value of auto storage class is garbage.
For E.g :-
void main( )
{
auto int a,b;
int c;
clrscr( );
printf(“Enter two numbers=”);
c = a + b;
printf(“Sum=%d”,c);
getch( );
}
Note: - As shown above a,b and c all are belong to the auto storage
class .
2) Static variable: - Static variable are those variable, which start
with static keyword. Static variables retain their values through out the
execution of the program. Their initial value is zero. Static variable also
use primary memory for storing data. Static variables are also active in
the block in which they are declared, means the scope of variable is

local. The declaration part of static variable execute only once even if
we call function more than once. Static variables are mostly used in
functions. As shown in example: -
#include <stdio.h>
#include<conio.h>
void show();
void main( )
{
clrscr( );
show( );
show( );
show( );
getch( );
}
void show( )
{
static int a;
printf(“n%d”,a);
a=a+1;
}
Output :- 0
1
2
3) Extern variable: - Extern variable are those variables, which
are, declared outside of the block/main. This variable can be accessible
by each block of the program. They are known as global variables.
These variables are declared with extern keyword. Its initial value is
zero. They consider as local variable but work as global variables. They
also use a primary memory (RAM) for storing a data.E.g :-
#include<stdio.h>
#include<conio.h>
void show();
void main( )
{
extern int a;
clrscr( );
show( );
a = a + 10;
printf(“nNow the value of a=%d”,a);
getch( );
}
void show( )
{
extern int a;

a=a + 5;
printf(“nThe value of a=%d”,a);
}
Output :- 0
5
15
4) Register variable: -Register variable are those variable, which
start with register keyword. We can use register keyword to increase
the speed of program. The Resister variable uses the CPU memory.
Their default value is garbage. They are also block level variables, which
can access with in the block where they are declared. In case of non-
availability of CPU memory, these variables use primary memory (RAM).
E.g :-
void main( )
{
register int a;
clrscr( );
printf(“nThe value of a=%d”,a);
getch( );
}
Difference between auto variable and a static variable
auto variable static variable
Auto variables are start with or
without auto keyword.
.Static variable start with static
keyword.
They cannot retain their value
throughout the execution of the
program.
They retains their value
throughout the execution of the
program.
Their default value is garbage. It’s default value is zero.
These variable initialize everytime
when we call the function.
These variable initialize a single
time and retain their value,
Example: auto int a; Example: static int a;
1. Explain the scope of variables in C?.
2. Give the difference between local and global variables in C?.
3. Explain the storage classes in C? Discuss their scope and use.
4. Discuss in brief, the difference between the following
declarations.
a. static int i;
b. auto int i;

Chapter 10
STRUCTURE
Structure is a group of similar and dissimilar data types. Structure is user
defined data type. To create a structure, we use struct keyword. Structure
starts with a delimiters ({) and close with a delimiter(}). After closing the
delimiters, we place a semicolon. To access the elements of the structures,
we create a structure variable/ structure field. With the help of structure
variable we use the dot operator and a specific element name, which we
want to access. As shown in the syntax below:
Syntax
struct<structure name>
{
<data type> <variable>;
<data type><variable>;
};
Example
struct student
{
char name[20];
int roll, marks ;
};
In this example student is structure name and in this structure we declare
two different data types , i.e. char & int.
Example of structure
#include<stdio.h>
#include<conio.h>
struct student
{
char name[20];
int roll,marks;
};
void main()
{
struct student s; //s is structure variable
clrscr();
printf(“enter student name”);
scanf(“%s”,&s.name);
printf(“enter student roll no”);
scanf(“%d”,&s.roll);
printf(“enter student marks”);
scanf(“%d”,&s.marks);
printf(“n your name=%s”,s.name);
printf(“n your roll=%d”,s.roll);
printf(“n your marks=%d”,s.marks);

getch();
}
Initialization of structure
Initialization of structure means to give the initial values to the structure
elements in place of giving the values at run time. As shown in the example
given below:
#include<stdio.h>
#include<conio.h>
struct student
{
char name[20];
int roll,marks;
};
void main()
{
struct student s={“Anju”,1,89}; //initialization of structure
variable s
clrscr();
printf(“n your name=%s”,s.name);
printf(“n your roll=%d”,s.roll);
printf(“n your marks=%d”,s.marks);
getch();
}
Memory representation in structure: - We can represent the memory
allocation of structure as given below. In it we can try to show the memory
presentation of structure.
struct student
{
char name[20];
int roll, marks;
};
name
0 1 2 3 4 ----------------------------------------- 16 17 18 19
roll
0 1
marks
0 1

As shown above it allocates 24 bytes memory for structure variables, 20
bytes memory for name, 2 bytes for roll number and 2 bytes for marks.
Total memory is 24 bytes.
Structure within array:- We can also declare an array variable inside the
structure. Structure and array both represents the group of elements. As
shown in the example
struct emp
{
char name[30];
char address[80]; //array
};
Dot Operator:- In structure we can use dot operator to access the elements
of the structure. We can use structure variable with dot operator and then
given the element name, which we want to access. As shown in the example
struct student s;
s.name=”MONCY”
s.marks=89;
Here s is the structure variable and name,marks are the elements of
structure which we are accessing using dot operator.
Structure Array
We can also create an array of the structure for storing the details of more
than one student.
struct student s[5];
Here s is the name of the structure array.The elements of this array are
s[0],s[1],s[2],s[3],s[4].
Write a program to enter the details of five students: their name, roll
no and marks using structure.
# include<stdio.h>
# include<conio.h>
struct student
{
char name [20];
int roll,marks;
};
void main( )
{
int i;
struct student s [5];
clrscr( );
for(i=0;i<5;i++)
{
printf(“n enter your name”);
scanf(“%s”,& s[i].name);
printf(“please enter roll no”);

scanf(“%d”,& s[i].roll);
printf(“please enter your marks”);
scanf(“%d”,& s[i].marks);
}
for(i=0;i<5;i++)
{
printf(“n your name=%s”,s[i].name);
printf(“n your roll no=%d”,s[i].roll);
printf(“nyour marks=%d”,s[i].marks);
}
getch( );
}
Nested structure
Nested structure means a structure inside a structure.It is possible to
have one structure as a member of another structure.In nested structure the
first structure is called the outer structure and second structure which inside
the structure is known as inner structure.E.g :-
struct emp
{
char name[20];
struct dep
{
int salary ;
}d;
};
void main( )
{
struct emp e;
clrscr( );
printf(“Enter Employ name=”);
sacnf(“%s”,& e.name);
printf(“Enter your salary=”);
sacnf(“%d”,& e.d.salary);
printf(“n Your name=%s”,e.name);
printf(“n Your salary=%d”.e.d.salary);
getch();
}
As shown in the above example the emp is our outer structure and dep is
inner structure.
Passing structure as argument into function: - We can also pass
structure as argument into the function. Same as variable and array. As
shown in the example.In this program,we write a function show().It accepts
a structure as its argument.

struct student
{
char name[30];
int roll, marks;
};
void show(struct student s);
void show(struct student s);
{
print(“n Student name=%s”,s.name);
print(“n Student roll=%d”,s.roll);
print(“n Student marks=%d”,s.marks);
}
void main()
{
struct student s={“Harparteek”,1,89};
clrscr();
show(s);
getch();
}
In the above example first we declare the structure and then declare the
function with structure argument. Then we define th body of the function
and in last call the function with main function.
To check the size of the structure
To check the size of the structure, we can use sizeof() operator. It tells us
how much memory is occupied by the structure elements.
As shown in the example below: -
#include<stdio.h>
#include<conio.h>
struct emp
{
char name[15];
int age;
float salary;
};
void main()
{
struct emp e;
clrscr();
printf(“the size of the structure=%d”,sizeof(e));
getch();
}

Difference between Structure And Array
Structure Array
Structure is a group of similar
and dissimilar elements.
Array is a group of elements of similar
types.
Structure starts with struct
keyword.
It does not start with any keyword but
is uses subscript for creating an array.
We can use dot operator to
accesses the elements of the
structure.
We can use index of the arrayto access
the element of the space array.
Structure has declaration and
definition.
It has only declaration.
5. Example
struct student
{
char name[20];
int roll;
};
5. Example
int a[10];
Important Short Answer type Questions
1. What are the advantages of structures?
2. What is structure?
3. Write a note on nested structure.
4. Explain self-referential structure.
5. Difference between structure and union.
1. Explain structure in C. How can you differentiate it from an
array?
2. How structures are defined and initialized? Explain with example.
3. Explain by giving example how the members of structure are
accessed in C.
4. What do you mean by structure within a structure? Give
Example.
5. Explain how structure can be passed to a function as argument
with example.
6. Write a program in C to define a structure student with data
members like rollno, class and marks of 5 students. Calculate total
marks and show the students detail.
7. Write a program to create a structure student having data
members as student name, rollno and pass it to a function as an
argument.

Chapter 11
UNION
Union is a group of similar and dissimilar data types or elements. It is a
user defined data type. Union starts with ‘union’ keyword and terminate with
semicolon same as structure. Union allocates a single memory to its
elements. All the elements of the union share the single memory. To access
the elements of union we can create a union variable. It is same as
structure.
The major difference between the union and structure is that in
structure different members use different memory locations whereas in
union all members of union share the same memory location.
Syntax: -
union < union name >
{
<data type> <variable name> ;
<data type> <variable name> ;
};
E.g: -
union student
{
char name [20];
int rollno, marks;
};
Union memory representation:- As we know that union allocate largest
memory of its element and it allocate a single memory to all it elements.
As shown in the figure and Example
union student
{
char name[20];
int roll, marks;
};
Memory representation
name
0 1 2 3 4 5 6 ------------------------- 17 18 19
roll
marks
As shown in the example and figure the union allocate 20 bytes memory for
name, roll and marks, which is the largest or higher memory in the union.
WAP to create union, which can store student detail like students
name, rollno, and marks.

union student
{
char name[20];
int rollno,marks ;
};
void main( )
{
union student s;
clrscr( );
printf(“Enter Employ name=”);
sacnf(“%s”,& s.name);
printf(“n Your name=%s”,s.name);
printf(“Enter your Rollno.=”);
sacnf(“%d”,& s.rollno);
printf(“n Your Rollno.is=%d”,s.rollno);
printf(“Enter your Marks=”);
sacnf(“%d”,& s.marks);
printf(“n Your Marks is=%d”,s.marks);
getch();
}
Initialization of union
We cannot initialize the union same as structure because it uses the
single memory location and all the elements use the same memory.
As shown in the example below:
#include<stdio.h>
#include<conio.h>
union student
{
char name;
int roll,marks;
};
void main()
{
union student s;
clrscr();
s.name='h'; //initialization of union variable s
printf("n your name=%c",s.name);
s.roll=1;
printf("n your roll=%d",s.roll);
s.marks=99;
printf("n your marks=%d",s.marks);
getch();
}

Union Array
We can also create the array of the union same as structure for storing
the details of more than one student.
Write a program to enter the detail of five students: their name,
rollno and marks using union.
# include<stdio.h>
# include<conio.h>
union student
{
char name [20];
int roll,marks;
};
void main( )
{
int i;
union student s[5];
clrscr( );
for(i=0;i<5;i++)
printf(“n enter your name”);
scanf(“%s”,& s[i].name);
printf(“n your name=%s”,s[i].name);
printf(“please enter roll no”);
scanf(“%d”,& s[i].roll);
printf(“n your roll no=%d”,s[i].roll);
printf(“please enter your marks”);
scanf(“%d”,& s[i].marks);
printf(“n your marks=%d”,s[i].marks);
}
getch( );
}
To check the size of the union
To check the size of the union we can use sizeof() operator. It tells us how
much memory is occupied by the union elements.
As shown in the example below:-
#include<stdio.h>
#include<conio.h>
union emp
{
char name[15];
int age;
float salary;
};
void main()
{

union emp e;
clrscr();
printf(“the size of the union=%d”,sizeof(e));
getch();
}
Difference between structure and union
Structure Union
Structure start with ‘struct’
keyword
Union start with ‘union’ keyword
All the elements of the structure
use different memory locations
for storing the data.
All the elements use the single
memory location for storing the
data.
It allocates different memory to
each element.
It allocates single memory. All the
elements share the same memory.
It is commonly used in most of
the applications.
It is not commonly used.
Syntax
struct <struct name>
{
};
Syntax
union <union name>
{
};
Important Short Answer Type Questions
1. State limitations of union.
2. Write advantages of union.
3. How we can check the size of union?
1. What is union? How can you differentiate it from a structure?
2. How union is defined and initialized? Explain with example.
3. Explain by giving example how the members of union are
accessed in C.
4. Write a program to define a union student with data members,
rollno as integer, stu_name as string and average marks as float.
Display the information of student and calculate the size of union.
5. What are the advantages of structure type over union type?

Chapter 12
ENUMERATION
The enumerated data type is used when we know in advance about a finite
list of values as a particular data type. The declaration of enumerated data
type start with ‘enum’ keyword.. ‘enum’ keyword is followed by an enum
name, an open brace, each of the values separated by a comma, and finally
a closing brace and a semicolon. The list of values is known as the
enumerated list of items.
Syntax: -
enum <enum name>{value1,value2,value3……….value n};
example:
enum color { red, blue, green, white, black };
Note:- Here color is the name of the enum, and red, green, blue are the
symbolic constants. Each enum constant has an integer value. If we have
not given any value, then the initial value of the red is 0, blue is 1 and so
on and incremented by one.
#include<stdio.h>
#include<conio.h>
enum col{red, green, blue, yellow, black, white };
void main()
{
clrscr();
printf(“n the value of red=%d”,red);
printf(“n the value of green=%d”,green);
printf(“n the value of white=%d”,white);
getch();
}
output:-
the value of red=0
the value of green=1
the value of white=5
Initialization of enum constant
We can also change the value of the each constant in the enum. Any
constant can be initialized with a particular value, and those that are
not initialized ,will be incremented automatically.
#include<stdio.h>
#include<conio.h>
enum col{red, green=5, blue, yellow, black, white };

void main()
{
clrscr();
printf(“n the value of red=%d”,red);
printf(“n the value of green=%d”,green);
printf(“n the value of white=%d”,white);
getch();
}
Output: -
the value of red=0
the value of green=5
the value of white=9
1. Give an example of enumerated data type in C.
1. Explain enum declaration in C with suitable example.
2. How can you differentiate enum from an array?
Chapter 13
POINTER
Pointer is a special type of variable, which is used to store the address of
another variable. This variable starts with asterisk symbol (*). The pointer
can use two special operators.
1. The first one is *(asterisk), it is called indirection operator or
value of operator.
2. The second is &(ampersand), it is called address of operator.
Pointer declaration
A pointer is declared same as a variable with a specific data type. But
declared with an asterisk sign. As show in the example below:
Example
int *ip; //ip is our integer pointer
float *fp; //fp is our Float pointer
char *cp; //cp is our character pointer
Address operator & (Ampersand)
As mentioned above, pointer uses two special operators; one of them is the
address operator, which is used to assign the address of the variable to the
pointer variable. As shown the example below:
int a,*ip;
a=5;
ip=&a; /*here we can assign the address of variable a
to pointer variable ip*/
Indirection operator * (asterisk)

Indirection operator is also known as value of operator, which is used to
print the value of the variable through pointer variable.The indirection
operator is used to declare a pointer. As shown in the example below:
int a,*ip;
a=5;
ip=&a;
printf(“n the value through pointer=%d”,*ip); /*here ip print the
value of a */
Complete example of pointer variable
# include<stdio.h>
# include<conio.h>
void main()
{
int a, *b;
clrscr();
a=5;
b=&a;
printf(“n the address of a=%u”,&a);
printf(“n the value of b=%u”,b);
printf(“n the value of b through pointer =%d”,*b);
getch();
}
output
the value of a=5
the address of a=65524
the value of b=65524
the value through pointer b=5
5 65524
a
65524
a is Variable
name
Address
of the
variable
a
Value
of the
variable
b
65526
Pointer
variable
Value of
pointer
variable
Address of
pointer
variable

Write a program to add two numbers using pointers.
#include<stdio.h>
#include<conio.h>
void main()
{
int a,,b,*c,*d, e;
clrscr();
printf(“enter the value of a=”);
scanf(“%d”,&a);
printf(“enter the value of b=”);
scanf(“%d”,&b);
c=&a;
d=&b;
e=*c + *d;
printf(“sum=%d”,e);
getch();
}
Write a program to swap two numbers using pointer without using
third variable.
#include<stdio.h>
#include<conio.h>
void main()
{
int a, b, *c, *d;
clrscr();
printf(“enter the value of a=”);
scanf(“%d”, &a);
printf(“enter the value of b=”);
scanf(“%d” , &b);
c=&a;
d=&b;
//swapping of two numbers
*c= *c+ *d;
*d= *c - *d;
*c= *c- *d;
printf(“after swapping the numbers”);
printf(“n now the value of a=%d”,a);
printf(“n now the value of b=%d”,b);
getch();
}
Arithmetic pointers
We can also use pointers for arithmetic purposes same as variables. When
we write a++ it increase the value of the variable but when we write p++,

it is a pointer variable it moves the pointer to the next memory location.
Like
int *p;
p++;
or
p=p+3;
Assume that the address of p is 65524.
When we add 3 to the pointer it move to the next location is 65527.
Note that we can perform any arithmetic operation on a pointer variable.
Pointers with array
The values of the array can be accessed with the help of pointer. Normally
we can assign the address of first element of an array to the pointer.
When we increment inside the pointer, it increments its address. It means
it reads the address of next element. The address of first element of an
array is called base address of array.
int a[]={2,4,3,5,6};
int *ip;
//here we can assign the address of array to the pointer.
ip=&a[0];
/*We can also assign the address of the first element to the pointer*/
ip=a;
//Here we need not to mention the index of the array.
Write a program to find the maximum number from the given array-
using pointer.
#include <stdio.h>
#include <conio.h>
void main()
{
int a[5],*p, i, b;
clrscr();
for(i=0;i<5;i++)
{
scanf(“%d”,&a[i]);
}
p=&a[0];
b=a[0];
for(i=0;i<5;i++)
{
if(*p>b)
{

b=*p;
}
p++;
}
printf(“the maximum number=%d”,b);
getch();
}
Pointer with strings
A string is a group of characters, which contain characters. We can access
the string-using pointer that read one character at time. We can assign the
address of first element of character array to the pointer.
As shown in the given example below:
Write a program to print your name-using pointer.
#include<stdio.h>
#include<conio.h>
void main()
{
char a[50]="Charanjiv Singh";
char *p;
clrscr();
p=a;
while(*p!='0')
{
printf("%c",*p);
p++;
}
getch();
}
Pointer with two Dimensional array
We can also access the two-dimensional array-using pointer in which
we can declare array with pointer.
As shown in the program: -
#include<stdio.h>
#include<conio.h>
void main()
{
int a[3][3],*p,i,j;
clrscr();
for(i=0;i<3;i++)
{

for(j=0;j<3;j++)
{
printf("enter any number");
scanf("%d",&a[i][j]);
}
}
p=&a[0][0];
for(i=0;i<3;i++)
{
for(j=0;j<3;j++)
{
printf("%d",*p);
p++;
}
printf("n");
}
getch();
}
Pointer with structure
We can also access the elements of the structure with help of pointer. We
can assign the address of the structure variable to the pointer variable. For
accessing the elements we can use arrow (->) operator in place of dot(.)
operator.
Write a program to access the elements of the structure-using
pointer.
#include<stdio.h>
#include<conio.h>
struct stu
{
char name[20];
int roll;
};
void main()
{
struct stu s={"Pratham",1};
struct stu *p;
clrscr();
p=&s;
printf("n your name=%s",p->name);
printf("n your roll=%d",p->roll);
getch();
}
Pointer to pointer
Pointer to pointer means which can store the address of another pointer
variable. A pointer-to-pointer variable start with double asterisk (**) sign. A

simple pointer can store the address of a variable but a pointer to pointer
can store the address of another pointer. As shown in the example below:
Example :-
int a, *p,**pp;
a=5;
p=&a;
pp=&p;
Example program
#include<stdio.h>
#include<conio.h>
void main()
{
int a,*p,**pp;
clrscr();
a=5;
p=&a;
pp=&p;
printf("nthe value of a=%d",a);
printf("nthe value of pointer =%d",*p);
printf("n the value of pointer to pointer=%d",**pp);
getch();
}
Pointer passing as argument to the Function
We can also pass pointer variable as an argument into the function. This is
also known as reference variables.
#include<stdio.h>
#include<conio.h>
void swap(int *a , int *b);
void swap(int *a, int *b)
{
*a=*a + *b;
*b=*a - *b;
*a=*a - *b;
}
void main()
{
int x,y;
clrscr();
printf(“enter the value of x”);
scanf(“%d”,&x);
printf(“enter the value of y”);
printf (“Before Swapping”);
printf(“n %d/n%d”,x.y);
scanf(“%d”,&y);

swap(&x ,&y);
printf(“n after swapping “);
printf(“n the value of x=%d”,x);
printf(“n the value of y=%d”,y);
getch(); }
Function Returning Pointer
A function can return a pointer same as it returns a variable. In this we can
declare and define the function with indirection (value of operator) operator.
As shown in the example given below
# include<stdio.h>
#include<conio.h>
int *show();
int *show()
{
int a;
scanf("%d", &a);
a=a*a;
return &a;
}
void main()
{
int *p;
clrscr();
p=show();
printf("n The value of a=%d",*p);
getch();
}
Advantages of Pointers
1. Pointers increase the speed of the program.
2. It is used to read the address of the variable.
3. It is used to the manage memory efficiently.
4. For Dynamic memory allocation we can use pointers.
5. With the help of pointers we can create efficient programs.
6. Pointers can be used to access elements of the structure.
7. It can pass as arguments into the function.
Difference Between A Variable And Pointer Variable
Variable Pointer variable
A variable starts with an alphabet. A pointer variable starts with an asterisk

sign.
It can store the value. It can store the address of another
variable
It can not use any special
operator.
It uses two special operators first is
address operator and second is
indirection operator(value of operator).
When we perform any arithmetic
operation on variable it increases
the value of the variable. Like
int a=5;
a++;
Now value of a=6.
when we perform any arithmetic
operation on pointer variable it moves to
the next memory address. It increments
in their address. Like int a=5,*p;
p=&a;
p++;
Now it increment in their address.
A float variable can store the value
of an integer variable.
A float pointer can store the address of
a float variable it cannot store the
address of integer variable.
Example
int a;
a=5;
Example
int *p,b=5;
p=&b;
It is also known as pointer variation. It mean the slightly difference between
the pointer variable and other variable
Dynamic memory allocation
Dynamic memory means, memory which is allocated at run time in place of
compile time. In normal array or variable, the memory is allocated at
compile time. It is known as static memory. The memory which is allocated
at run time is known as dynamic memory. This memory is accessed using
pointer. For dynamic memory we can use various methods, which are stored
in the alloc.h header file.These function are:-
1. malloc() function
2. calloc () function
3. realloc() function
4. free() function
1. malloc()Function:- malloc means memory allocation function.
This function is used to allocate dynamic memory at run time to the
pointer variable. This function allocates a single block of memory of
specific data type. As shown in the example below:
Write a program to print the elements of pointer using malloc
function
#include<stdio.h>
#include<conio.h>

#include<alloc.h>
void main()
{
int i, n,*p;
clrscr();
printf("enter the size of the values");
scanf("%d",&n);
p=(int*) malloc(n);
for(i=0;i<n;i++)
{
scanf("%d",(p+i));
}
for(i=0;i<n;i++)
{
printf("%dn",(*p));
p++;
}
getch();
}
2. Calloc() Function:- This function is also used for dynamic memory
allocation same as malloc function but this function contain two
arguments. The first argument tells the number of elements(items) and
the second argument tells their size. It allocates number of blocks
memory. As shown in the syntax and example program given below:
void calloc(number of items, size);
#include<stdio.h>
#include<conio.h>
#include<alloc.h>
void main()
{
char *p=NULL;
clrscr();
p=(char*) calloc(10,sizeof(char));
printf("enter any string");
scanf("%s",p);
printf("%s",p);
getch();
}
3. Realloc() Function:- Realloc function means reallocation of memory.
This function is used to reallocate memory to the preallocated pointer
variable. This function is used to increase and decrease the size of the
memory. As shown in the syntax and example below:

#include <stdio.h>
#include <alloc.h>
#include <string.h>
#include<conio.h>
void main()
{
char *p;
clrscr();
p = (char *) malloc(10);
strcpy (p, "CJSOFTECH");
printf("String is %s”,p);
printf(“n Address is %u”, p);
p = (char *) realloc(p, 20);
strcpy(p,"CJSOFTECH Patiala");
printf(“String is %s”,p);
printf(“n New address is %u",p);
getch();
}
4. Free function:- This function is used to release the memory which is
occupied by the variable. That memory, which is allocated by the above
discussed functions like malloc(), calloc(), realloc(), so this function is
used to free the memory. This function contains a single argument,
whose memory we want to release. As shown in the syntax and example
below:
void free (pointer variable);
Example
free(*p);
1. List the applications of pointers in C.
2. What is indirection operator?
3. What is address of operator?
4. What are the advantages of pointers?
5. What is the significance of calloc function in C?
6. What is dynamic memory allocation?
7. What do you mean by pointer to pointer?
8. Why pointer is called double edge weapon? Explain.
1. Explain with examples the pointer concept in C. State the advantages
of pointers in C.

2. What is a pointer? Explain the difference between simple variable and
pointer variable.
3. Demonstrate how pointer can be used to access data of a structure.
4. Describe how pointers are used for handling character string.
5. Write C program-using pointers to find the greatest of given three
numbers.
6. Write C program-using pointers to sort the given list of number in
ascending order.
7. What do you mean by dynamic memory allocation. Explain different
methods used for dynamic memory allocation.
CJ SOFTECH Walia EnclaveCJ SOFTECH Walia EnclaveCJ SOFTECH Walia EnclaveCJ SOFTECH Walia Enclave
Opp Punjabi Univ PatialOpp Punjabi Univ PatialOpp Punjabi Univ PatialOpp Punjabi Univ Patiala.a.a.a.
# 3058# 3058# 3058# 3058 Urban Estate PhaseUrban Estate PhaseUrban Estate PhaseUrban Estate Phase –––– 2222

Chapter 14
FILE HANDLING IN C
To understand the concept of File handling, we must understand the
following things;
1. Data : Raw information is called data. For example student
name, father’s name, address, dob, rollno etc. Each individual item is
called data.
For example
Name is a data, rollno is a data, dob is a data. In electricity dept
person name, address, meter no is a data.
2. Record: Record is a collection of data of same type. It is a
detail of data. For example all things in your admission form name,
fname, dob, rollno, marks of yours together is known as record.
For example (navjeet, s. karamjit singh, 2-08- 1983, 1. 89). It is a
record of a single student.
In one record data should be of same concerned item or thing or
person.
In one record we cannot mix data of different things.
Eg; name of ram
Roll no of sham
This is wrong. Here Roll No and Name must be of same person.
Now you see two different records
Student’s Record Record in Electricity dept
Suppose these two different records are of yours. Name, Ph.no,
Address is common. But Roll no, meter no is different that’s why we
create different records.
3. File : File is a collection of similar same type of records. For
example student’s records will be placed in a one file. (Student name,
Address, father’s name, phno, rollno, school name)
Electricity dept will hold records of bill in different file(Person Name,
Address , Ph No, Meter No, Old Reading, New Reading)
Note
Person name
Address
Ph No
Meter No
Old Reading
New
Reading
Student name
Address
Father’s Name
Ph No
Roll No
School Name
D
A
T
A

We cannot mix different records in a one file. To maintain different
records we need to maintain different records. That’s why we need to
maintain different files.
Diagram of file
In earlier days, the amount of information is stored in manual form. The
major drawbacks of manual system are Required more space to store the
data in file Updating of data was very difficult.
Searching is quite difficult.
No security in manual Files Manual file were not reliable means if file was
lost all the data would also lost.
Now modern files are made on computers. The data is stored in
computerized files.
It has following advantages;
1. Data can be easily stored in compact space updating of data is
very easy. Using the pointers concept when we perform any changes
in a file, all the files which related with that file are automatically
updated.
2. Searching is very easy.
3. The data in modern file are very secure. Only the authorized
persons can view data.
4. Files are very reliable because adequate backup checks are
there.
The main motive of file handling is to transfer the data from primary
memory to secondary memory.
Types of Files
There are three types of files, which are;
Data
Data
Data
Data
Data
Data
Data
Data
1 record
2nd
record
Name
Father’s Name
Address
Ph No
DOB
City
School
Marks
(N records mark 1 file)
N records
3rd
record

1. Text Files
2. Data Files
3. Binary Files
1. Text Files: - Text files are those files, which store the information in
the text format. It stores the data into character or strings. The
extension of text file is .txt.
2. Data Files: - Data files are known as database files, which store the
data in different formats. The extension of data file is .dat.
3. Binary Files: - These files store data in binary form. These files store
data in sequence of bytes. It is an Encrypted file so we cannot read it.
FILE Structure
FILE is our inbuilt structure, which is used to create a file. We can create a
pointer of the FILE structure. It is known as file declaration. As shown in the
example and syntax.
Syntax:-
FILE filepointer;
Example:-
FILE *fp;
Note: The type name FILE is always written in capital letters
File handling Functions
1. fopen() functon:- Before using data file it is necessary to open
that file. It can be opened by using fopen() function. The function has
two arguments, first is name of the file to be opened , and second is
string representing mode in which the file is to be opened. As shown in
the syntax and example given below:
Syntax:-
fp=fopen(“filename”,”mode”);
e.g.
fp=fopen(“CJSOFTECH.txt”,”w”);
File name: - It specifies the file name where we want to store the
data. Like “CJSOFTECH.txt”, here CJSOFTECH is the file name and .txt
its extension. It means it is a text file.
Modes: -File can be opened in following modes:
1. Read: - In this mode we can read the data from the file. When
a file is opened in this mode, it is not possible to write the data into the
file. We can use ”r” as a parameter in fopen function.
2. Write: - If a file in this mode is opened we can write the data
into the file but it is not possible to read the data from file. A file
already exists is opened in the write mode, the old contents of the file
will be deleted and new data can be written in the file. We can use ”w”
as a parameter in fopen function.

3. Append: - If a file in this mode is opened we can add the data
into the file at the end of the file. Parameter used in fopen is “a”.
r+ mode:- To open the file for reading and writing the data.
w+ mode:- To open the file for writing. Data can be read after writing.
a+ mode:- To open the file ,write the data at the end of the file. Data
can be read after writing.
2. fclose() function:- It is used to close a file. This function
contains a single argument, which is the file pointer. As shown in the
syntax and example given below:
Syntax: -
fclose(file pointer);
Example:
fclose(fp);
3. fputs() function:- It is used to write a string into the file. This
function contains two arguments first is string and second is the file
pointer. As shown in the syntax and example
Syntax : -
fputs(string, file pointer);
Example:-
fputs(str, fp);
4. fgets() function:- This function is used to read the data from a
file in string format. This function contains three arguments. First is
string in which data is stored, second argument is the length of the
string and third is the file pointer (fp). As shown in the syntax and
example
Syntax: -
fgets(string, length, file pointer);
Example: -
fgets(str,40,fp);
5. getc() Function:- This function is used to read a character from a
file. This function contains a single argument of file pointer. As shown in
the syntax and example-
Syntax: -
variable=getc(file pointer);
Example:
char a;
a=getc(fp);
Note:
The character read from the file is assigned to a char variable a.
6. putc() Function:-This function is used to write a character to a
file. It has two arguments, first is the character variable and second is
the file pointer. As shown in the example:-
Example:char a;
putc(a,fp);
Note:

The value of a char variable ‘a’ is written in the file.
7. getw () Function:- This function is used to read an integer
from a file. This function also contains a single argument, which is the
file pointer. As shown in the example: -
a=getw(fp);
8. putw() Function:- This function is used to write an integer to a
file. This function contain two arguments, first is the integer variable
and second is the file pointer. As shown in the example: -
putw(a,fp);
9. feof function :- feof means file end of file. This function reads
the file till end. This function returns a negative number when we reach
at the end of the file. As shown in the example:-
while(feof(fp)!=-1)
Write a program to store the data in the file using fputs() function.
include<stdio.h>
include<conio.h>
void main()
{
char str[32];
FILE *fp;
clrscr();
printf(“enter any string”);
gets (str);
puts(str,fp);
printf(“data is written into the file”);
fclose(fp);
getch(); }
WAP to read the data from a file using fgets() function.
include<stdio.h>
include<conio.h>
void main()
{
char str[32],*p;
FILE *fp;
clrscr();
fp=fopen(“CJSOFTECH.txt”,”r”);
while((p=fgets(str,40,fp))!=’0’)
{
printf(“%s”,str);
}
fclose(fp);
getch(); }
WAP to copy the contents of one file into another file.
include<stdio.h>

include<conio.h>
void main()
{
char str[32],*p;
FILE *fp,*fp1;
clrscr();
fp=fopen(“CJSOFTECH.txt”,”r”);
fp1=fopen(“CJSOFTECH.txt”,”w”);
while((p=fgets(str,40,fp))!=’0’)
{
fputs(str,fp1);
}
fclose(fp);
printf(“data is copied”);
fclose(fp1);
getch();
}
Write a program to write Integer data in a Binary file.
void main()
{
FILE *fp;
int i;
clrscr();
fp=fopen("CJSOFTECH.dat","w");
for(i=1;i<=10;i++)
{
putw(i,fp);
}
printf("data is written");
fclose(fp);
getch();
}
Write a program to read integer data from a Binary file.
#include<stdio.h>
#include<conio.h>
void main()
{
FILE *fp;
int n;
clrscr();
fp=fopen("CJSOFTECH.dat","r");
while((n=getw(fp))!=EOF)
{

printf("%d",n);
}
fclose(fp);
getch();
}
Random Access Files
Random access file are those files in which we can read and write the data at
random location. But in some situation, when we need to access the data
from a specific part of a file., then we use fseek(), ftell(), and rewind()
functions.
1. fseek() Function:- fseek function is used to move the file
pointer to a desired location within the file. This function contains
three arguments . The first argument is the file pointer, second
argument tells how many bytes move in the file and third argument
tells the current position of the pointer. As shown in the syntax: -
fseek(file pointer, n, position);
2. ftell() Function:- This function tells us the current position of
the pointer. This function contains a single argument of file pointer. As
shown in the given syntax:-
n=ftell(file pointer);
3. rewind() Function:- This function is used to set the pointer or
cursor in the beginning of the file. This function contains a single
argument of file pointer. As shown in the syntax:
rewind(fp);
Error Handling during input/output operations
Error is occurring during input/output operation of the file when an
error is occurred in the program the program is terminated. There are
so many reasons for an error like file not found, null pointer etc.
Error Handling
Error handling means to solve the problem or to remove the errors
with the help of inbuilt function, which are provided us by the
programming language.
NULL: - This help us to check if the file is exist or not. If file
does not exist then it equal to null. As shown in the example:-
FILE *fp;
Fp=fopen(“CJSOFTECH.txt”,”r”);
If(fp==NULL)
{
printf(“File doesn’t exist”);
exit(0);
}
else
{
Read the file contents” }

ferror():- This is known as file error function. This function is
used when we access the file, if there is any problem in accessing the
file then this function returns a positive or negative number. But when
there is no problem in accessing the file then it returns zero. As shown
in the example: -
FILE *fp;
if (ferror(fp)==0)
{
printf(“No problem in file accessing”);
}
else
{
printf(“There is problem in file accessing”);
}
EOF():- This is known as End of file. This function is used to
check the file end. In place of EOF we can use –1. It is same as end of
file; when our cursor reach as the end of the file then it returns a
negative number –1 or EOF. As shown in the example:-
FILE *fp;
int a;
fp=fopen*(“CJSOFTECH.txt”,”r”);
While(a=getw(fp)!=EOF)
{
printf(“n %d”,a);
}
1. List down two file opening modes in C?
2. What are random access files?
3. What is a FILE?
4. What are the advantages of data file over other data types?
5. Difference between fseek() and ftell() function.
1. Explain various File Handling Functions available in C.
2. Write a C program to read a text from the file and display it on
the screen.
3. Write a C program to copy the contents of a file into another
file and also update that file.
4. Discuss in brief getw(), putw() functions.
5. Distinguish between append mode and write mode.
6. State the difference between Sequential Files and Random
Access Files.
7. Explain character input/output handling functions.
8. Write a C program to create a file containing integers and
display them.
9. What is the advantage of using a data file?

Chapter 15
MACRO
Macro is also called a substitution string. A macro always start with #
define. After the # define, we can give the name to the macro and after that
we can give replacement text/value. Wherever the preprocessor encounters
that name, it will replace it with the replacement text. Macro is always
declared in capital letters, which differentiate the macro from variable. If we
want to change the value of the macro variable we can do it at only at place
where it is defined. Macro never ends with semicolon.
The value of the macro body specified by a #define directive can be any
character string or number. For example, the following definition is NAME
with the string "CJSOFTECH".
SYNTAX:
#define <identifier><value>
Example:-
#define A 50
WAP to use macro in the program.
#include<stdio.h>
#include<conio.h>
#define a 10
void main()
{
int b;
clrscr();
b=a*a;
printf(“square=%d”,b);
getch();
}
In macro we can also pass arguments inside the macro. It works as function,
which are defined before using it.
Write a program to swap two numbers without using third variable
and by using macro.
#include<stdio.h>
#include<conio.h>
#define swap(x,y)x=x+y;y=x-y;x=x-y
void main()
{
int a,b;
clrscr();
printf(“enter two no”);
scanf(“%d%d”, &a,&b);
swap(a,b);
printf(“n now value of a=%d” ,a);
printf(“n now value of b=%d”,b);

getch();
}
Typedef
Definition: - Typedef means to rename the existing data type. With the
help of ‘typedef’ we can give the new name to the inbuilt data type
/structure typedef declaration does not declare any new data type which
does not exist in the C language. Typedef means to create new definition
name of an existing data type.
SYNTAX: -
typedef<data type><new data type>;
Example: -
typedef int cj ;
Example:-
#include<stdio.h>
#include<conio.h>
void main()
{
typedef int cj;
clrscr();
cj a,b,c;
printf(“enter two numbers”)
c=a+b;
printf(“sum=%d”,c);
getch();
}
Command Line Arguments
Command line arguments is the another way to input the values into our
program using console instead of using scanf() function. In C ,mostly we use
scanf() to input the values into the program. Command line arguments are
the values passed into the main function from command line (Dos prompt).
We can pass two arguments to the main() function:
1. argc : integer type argument
Indicates the number of parameters passed.
2. argv : array of strings
Each string in this array will represent a parameter that is passed to
main().
CJ SOFTECH WaliaCJ SOFTECH WaliaCJ SOFTECH WaliaCJ SOFTECH Walia Enclave Opp Punjabi Univ Patiala.Enclave Opp Punjabi Univ Patiala.Enclave Opp Punjabi Univ Patiala.Enclave Opp Punjabi Univ Patiala.

As shown in the program below:
#include<stdio.h>
#include<conio.h>
void main(int argc,char *argv[])
{
int i;
clrscr();
for(i=1;i<argc;i++)
{
printf("%s",argv[i]);
}
getch();
}
Steps to execute the program
1. After typing the program save the file with .c extension.
2. Now compile the program using ALT+F9.
3. Now click on file menu and select “Dos shell” option.
4. Now first type file name and then type number of arguments.
Example: -
C:tcbin> filename one two three
Note: -Here CJSOFTECH is the file name and one ,two three are
arguments
5. Now press enter key.
To go back to the C program type “exit” and press enter key
Imp Short Answer Type Questions
1. Define Macro.
2. Write a note on typedef.
3. What are command line arguments?
4. Why do we use #define?
5. WAP to create a macro to find the square of a number.

CJ SOFTECHCJ SOFTECHCJ SOFTECHCJ SOFTECH
Walia EnclaveWalia EnclaveWalia EnclaveWalia Enclave
Opp Punjabi UnivOpp Punjabi UnivOpp Punjabi UnivOpp Punjabi Univ
Patiala.Patiala.Patiala.Patiala.
# 3058# 3058# 3058# 3058 UrbanUrbanUrbanUrban
Estate PhaseEstate PhaseEstate PhaseEstate Phase –––– 2222

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