Unit 1 c - all topics

Computer -- Hardware
Key board
Mouse
Input Devices
Monitor
Printer
Output Devices
Secondary Storage Devices
Input
Storage
Area
Program Storage Area
Output
Storage
Area
Working Storage Area
Primary or Main Memory (RAM)
Register 1
Arithmetic
and
Logic Unit
Register 2
……
……
Register N
Micro Processor

Algorithm: Step by step procedure of solving a particular problem.
Pseudo code: Artificial informal language used to develop algorithms.
Flow chart: Graphical representation of an algorithm.
Algorithm to find whether a number even or odd:
Step1: Begin Step1: START
Step2: Take a number Step2: Read num
Step3: if the number is divisible by2 then Step3: if(num%2=0) then
print that number is even print num is even
otherwise print that number is odd otherwise
print num is odd
Step4: End Step4: STOP
(Algorithm in natural language) (Algorithm by using pseudo code)
#include<stdio.h>
#include<conio.h>
main()
{
int num;
printf(“Enter any number”);
scanf(“%d”,&num);
if(num%2==0)
printf(“%d is even”,num);
else
printf(%d is odd”,num);
}
(Program in C language)
start
read num
print num
is even
stop
If numIf num
%2=0%2=0
print num
is odd
Flow chart:Flow chart:
YesYes NoNo

Flow chart symbols
Oval Terminal
Parallegram Input/output
Rectangle Process
Document Hard copy
Diamond Decision
Circle Connector
Double sided Rectangle Sub program
Hexagon Iteration
Trapezoid Manual Operation
Cylinder Magnetic Disk Storage

Machine Language – Assembly Language – High-Level Language
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entry main,^m<r2>
sub12 #12,sp
jsb C$MAIN_ARGS
moveb $CHAR_STRING_CON
pusha1 -8(fp)
pusha1 (r2)
calls #2,SCANF
pusha1 -12(fp)
pusha1 3(r2)
calls #2,SCANF
mull3 -8(fp),-12(fp),-
pusha 6(fp)
calls #2,PRINTF
clrl r0
ret
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00000000 00000100 0000000000000000
01011110 00001100 11000010 0000000000000010
11101111 00010110 0000000000000101
11101111 10111110 0000000000001011
11111000 10101101 11011111 0000000000010010
01100010 11011111 0000000000010101
11101111 00000010 11111011 0000000000010111
11110100 10101101 11011111 0000000000011110
00000011 10100010 11011111 0000000000100001
11101111 00000010 11011111 0000000000100100
01111110 11110100 10101101
11111000 10101110 11000101 0000000000101011
00000110 10100010 11111011 0000000000110001
11101111 00000010 11111011 0000000000110100
01010000 11010100 0000000000111011
00000100 0000000000111101
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1
0
#include<stdio.h>
int main(void)
{
int n1, n2,product;
printf(“Enter two numbers : “);
scanf(“%d %d”,&n1,&n2);
product = n1 * n2;
printf(“%d”,product);
return 0;
}
The only language the computer can understand is machine
language (binary language).
A high level language is an English like language where one
instruction typically translates into a series of machine-
language instructions.
A low level language corresponds closely to machine code so
that a single low-level language instruction translates to a
single machine language instruction.

Language Translation
• Translator
– is a computer program that reads a
program written in one language,
which is called the source
language, and translates it in to
another language, which is called
the target language.
• Assembler
• Compiler
• Assembler
– Assembler is a software or a tool
that translates Assembly language
to machine code.
• Compiler
– Compiler is a program that
translates High level language such
as programs written in C, C++ to
machine code

Difference between Compiler
and Interpreter
No Compiler Interpreter
1 Compiler Takes Entire program as input
Interpreter Takes Single instruction as
input .
2 Intermediate Object Code is Generated No Intermediate Object Code is Generated
3
Conditional Control Statements are
Executes faster
Conditional Control Statements are
Executes slower
4
Memory Requirement : More(Since
Object Code is Generated)
Memory Requirement is Less
5 Program need not be compiledevery time
Every time higher level program is
converted into lower level program
6
Errors are displayed after entire
program is checked
Errors are displayed for every
instruction interpreted (if any)
7
Example : C Compiler [Eg. cc, gcc,
ANSI C, Borland C, etc.]
Example : Python Interpreter (Eg. IDLE,
etc.)

Structure of C program
/*Program to find/*Program to find
area and perimeter of Circle */area and perimeter of Circle */
#include<stdio.h>#include<stdio.h>
#define PI 3.1415#define PI 3.1415
float radius;float radius;
float area();float area();
float perimeter();float perimeter();
int main()int main()
{{
float a, p;float a, p;
printf(“Enter radius : “);printf(“Enter radius : “);
scanf(“%f”,&radius);scanf(“%f”,&radius);
a = area();a = area();
p = perimeter();p = perimeter();
printf(“Area of Circle : %f”,a);printf(“Area of Circle : %f”,a);
printf(“Perimeter : %f”,p);printf(“Perimeter : %f”,p);
}}
float area()float area()
{{
return (PI * radius * radius);return (PI * radius * radius);
}}
float perimeter()float perimeter()
{{
return (2 * PI * radius);return (2 * PI * radius);
}}
Documentation/Comment SectionDocumentation/Comment Section
Linkage/header file SectionLinkage/header file Section
Definition SectionDefinition Section
Global Declaration SectionGlobal Declaration Section
Main Function SectionMain Function Section
Local Declaration PartLocal Declaration Part
Executable Code PartExecutable Code Part
Sub Program SectionSub Program Section
Function1()Function1()
Function2()Function2()
…………………………
FunctionN()FunctionN()

Preprocessor DirectivesPreprocessor Directives

99
Compilation & Linking
helloworld.chelloworld.c
stdio.hstdio.h
#include <stdio.h>#include <stdio.h>
helloworld.ohelloworld.o
Helloworld.exeHelloworld.exe
header fileheader file
compilercompiler
linkerlinker
executable fileexecutable file
object fileobject file
source filesource file

Program Development Steps
1)Statement of Problem
a) Working with existing system and using proper
questionnaire, the problem should be explained
clearly.
b) What inputs are available, outputs are required
and what is needed for creating workable solution
should be understood clearly.
2)Analysis
a) The method of solutions to solve the problem can
be identified.
b) We also judge that which method gives best
results among different methods of solution.
3)Designing
a) Algorithms and flow charts will be prepared.
b) Keep focus on data, architecture, user interfaces
and program components.
4)Implementation
The algorithms and flow charts developed in the
previous steps are converted into actual programs in
the high level languages like C.
4.a)Compilation
Translate the program into machine code. This
process is called as Compilation. Syntactic errors are
found quickly at the time of compiling the program.
These errors occur due to the usage of wrong
syntaxes for the statements.
Eg: x=a*y+b
There is a syntax error in this statement, since, each
and every statement in C language ends with a
semicolon (;).
4.b)Execution
The next step is Program execution. In this phase, we
may encounter two types of errors.
Runtime Errors: these errors occur during the
execution of the program and terminates the program
abnormally.
Logical Errors: these errors occur due to incorrect
usage of the instructions in the program. These errors
are neither detected during compilation or execution
nor cause any stoppage to the program execution but
produces incorrect ouz

Executing a C program
compiles
Syntax
Errors?
Yes
Object machine code
010110 100
…………….
01011 101
C-compiler
#include<stdio.h>
int main()
{
…….
Text
Editor
prog1.c
prog1.obj
Linker
Executable
machine code
00101010
………….
01010101
adds
Translators are system software
used to convert high-level
language program into
machine-language code.
Compiler : Coverts the entire
source program at a time
into object code file, and
saves it in secondary storage
permanently. The same
object machine code file will
be executed several times,
whenever needed.
Interpreter : Each statement of
source program is translated
into machine code and
executed immediately.
Translation and execution of
each and every statement is
repeated till the end of the
program. No object code is
saved. Translation is
repeated for every execution
of the source program.
machine code of
library file
Input
prog1.exe
No
C-Runtime
Executes
Feeds
Runtime
or Logic
Errors ?
Yes
Output

C-Language Keywords
auto double int struct
break else long switch
case enum register typedef
char extern return union
const float short unsigned
continue for signed void
default goto sizeof volatile
do if static while
inline
Character Set of C-Language
Alphabets : A-Z and a-z
Digits : 0-9
Special Symbols : ~ ! @ # $ % ^ & ( ) _ - + = | { } [ ] : ; “ ‘
< > , . ? /
White Spaces : space , Horizontal tab, Vertical tab, New Line
Form Feed.

C-Tokens
Tokens : The smallest individual units of a C- program are called Tokens.
Key words, Identifiers, Constants, Operators, Delimiters.
Key words : have a predefined meaning and these meanings cannot be
changed. All keywords must be written in small letters.
Identifiers : names of variables, functions, structures, unions, macros, labels,
arrays etc.,
Rules for define identifiers :
a) First character must be alphabetic character or under score
b) Second character onwards alphabetic character of digit or under
score.
c) First 63 characters of an identifier are significant.
d) Cannot duplicate a key word.
e) May not have a space or any other special symbol except under
score.
f) C – language is Case-sensitive.

C-Tokens
Constants : fixed values that do not change during execution of a program.
Boolean constants : 0 ( false) and 1 (true)
Character constants :
only one character enclosed between two single quotes
( except escape characters ).
Integer constants : +123, -3454 , 0235 (octal value),
0x43d98 ( hexa - decimal value)
54764U, 124356578L, 124567856UL
Float constants : 0.2 , 876.345, .345623 , 23.4E+8, 47.45e+6
String Constants : “Hello world” , “Have a nice day!”
Complex Constants : real part + imaginary part * I ex : 12.3 + 3.45 * I
Operators : a symbol, which indicates an operation to be performed.
Operators are used to manipulate data in program.
Delimiters : Language Pattern of c-language uses special kind of symbols
: (colon, used for labels) ; (semicolon terminates statement ) ( ) parameter list
[ ] ( array declaration and subscript ), { } ( block statement )
# ( hash for preprocessor directive ) , (comma variable separator )

printf() & scanf() functions
int main ( )
{
printf(" %d", printf("%s", “welcome"));
return 0 ;
}
int main()
{
char a;
printf("%d",scanf("%c",&a));
return 0;
}
Returned values of printf() and scanf()
In C,
•printf() returns the number of characters successfully written on the output
•scanf() returns number of items successfully read.
Irrespective of the character that user
enters, this program prints 1
This program prints welcome 7

Careful to use scanf()
• The basic problem is that scanf() leaves the
newline after the number in the buffer, and
then reads it with %c on the next pass.
• This is a good demonstration of why we
need to cautious about to use scanf()

Conversion/Access/fomat Specifiers
CodeCode FormatFormat
%s String of characters (until null zero is reached )
%c Character
%d Decimal integer
%f Floating-point numbers
%e Exponential notation floating-point numbers
%u Unsigned integer
%o Octal integer
%x Hexadecimal integer
%i Signed decimal integer
%p Display a pointer
%hd short integer
%ld long integer
%lf long double
%% Prints a percent sign (%)

Back Slash ( Escape Sequence) Characters
Code Meaning
b Backspace/non-erase
f Form feed
n New line
r Carriage return/clear screen
t Horizontal tab
" Double quote
' Single quote
Backslash
v Vertical tab
a Alert/bell sound (speaker beeps)
? Question mark

Data Types ( pre-defined )
Type Typical Size in Bits Minimal Range
char 8 –127 to 127
unsigned char 8 0 to 255
signed char 8 –127 to 127
int 16 or 32 –32,767 to 32,767
unsigned int 16 or 32 0 to 65,535
signed int 16 or 32 Same as int
short int 16 –32,767 to 32,767
unsigned short int 16 0 to 65,535
signed short int 16 Same as short int
long int 32 –2,147,483,647 to 2,147,483,647
long long int 64 –(263
) to 263
– 1 (Added by C99)
signed long int 32 Same as long int
unsigned long int 32 0 to 4,294,967,295
unsigned long long int 64 264
– 1 (Added by C99)
float 32 3.4e-38 to 3.4e+38
double 64 1.7e-308 to 1.7e+308
long double 80 3.4e-4932 to 1.1e+4932
void -- data type that not return any value

Value range of different types
Type Storage size Value range
char 1 byte -128 to 127 or 0 to 255
unsigned char 1 byte 0 to 255
signed char 1 byte -128 to 127
int 2 or 4 bytes -32,768 to 32,767 or -2,147,483,648 to
2,147,483,647
unsigned int 2 or 4 bytes 0 to 65,535 or 0 to 4,294,967,295
short 2 bytes -32,768 to 32,767
unsigned short 2 bytes 0 to 65,535
long 4 bytes -2,147,483,648 to 2,147,483,647
unsigned long 4 bytes 0 to 4,294,967,295

Data type modifiers in C
Used to change the properties of current properties ofUsed to change the properties of current properties of
data type. Data type modifiers are classified intodata type. Data type modifiers are classified into
following types.following types.
•longlong
•shortshort
•unsignedunsigned
•signedsigned

Data type modifiers in C
Modifiers are prefixed with basic data types to modify (eitherModifiers are prefixed with basic data types to modify (either increase orincrease or
decreasedecrease)) the amount of storage space allocated to a variablethe amount of storage space allocated to a variable..
For exampleFor example, storage space for, storage space for int data type is 4 byteint data type is 4 byte for 32 bit processor.for 32 bit processor.
We canWe can increaseincrease the range by usingthe range by using long int which is 8 bytelong int which is 8 byte. We can. We can
decreasedecrease the range by usingthe range by using short int which is 2 byteshort int which is 2 byte..

Precedence and Associativity of Operators
Precdence Group Operators Associativity
(Highest to Lowest )
(param) subscript etc., ( ) [ ] –>. L  R
Unary operators - + ! ~ ++ – – (type) * & sizeof R  L
Multiplicative * / % L  R
Additive + – L  R
Bitwise shift << >> L  R
Relational < <= > >= L  R
Equality = = != L  R
Bitwise AND & L  R
Bitwise exclusive OR ^ L  R
Bitwise OR | L  R
Logical AND && L  R
Logical OR | | L  R
Conditional ?: R  L
Assignment = += –= *= /= %= &= ^= R  L
|= <<= >>=
Comma , L  R

Conditional/Decision Control
Statements
• Simple if
• if… else
• nested if… else
• If else ladder
– if… else if… else

TestTest
ExpressionExpression
??
EntryEntry
FalseFalse
Next statementNext statement
True Statement-blockTrue Statement-block
TrueTrue
simple if:simple if:
TestTest
ExpressionExpression
??
EntryEntry
True-blockTrue-block
StatementsStatements
FalseFalse
False-blockFalse-block
StatementsStatements
TrueTrue
if-else:if-else:
/* check a citizen is eligible for voting *//* check a citizen is eligible for voting */
{{
int age;int age;
printf(“Enter the age : ”);printf(“Enter the age : ”);
scanf(“%d”,&age);scanf(“%d”,&age);
if(age >= 18)if(age >= 18)
printf(“Eligible for voting…”);printf(“Eligible for voting…”);
getch();getch();
}}
/* print a number is even or odd *//* print a number is even or odd */
{{
int number;int number;
printf(“Enter a number : “);printf(“Enter a number : “);
scanf(“%d”, &number);scanf(“%d”, &number);
if((number %2) == 0)if((number %2) == 0)
printf(“%d is even number.”,number);printf(“%d is even number.”,number);
elseelse
printf(“%d is odd number.”,number);printf(“%d is odd number.”,number);
}}

TestTest
condition1condition1
??
EntryEntry
Statement-3Statement-3
TrueTrue
TestTest
??
FalseFalse
Statement-2Statement-2 Statement-1Statement-1
TrueTrue
FalseFalse
nested if…else:nested if…else: /* check whether a year is leap year or not *//* check whether a year is leap year or not */
int main() {int main() {
int year;int year;
printf("Enter the year ?");printf("Enter the year ?");
scanf("%d",&year);scanf("%d",&year);
if((year %100) == 0)if((year %100) == 0)
{{
if((year % 400) == 0)if((year % 400) == 0)
printf("%d is leap year.",year);printf("%d is leap year.",year);
elseelse
printf("%d is not leap year.",year);printf("%d is not leap year.",year);
} else {} else {
if((year % 4) == 0)if((year % 4) == 0)
printf("%d is leap year.",year);printf("%d is leap year.",year);
elseelse
printf("%d is not leap year.",year);printf("%d is not leap year.",year);
}}
getch();getch();
}}

if…else…if :if…else…if :
EntryEntry
TestTest
??
TrueTrue
TrueTrue
TestTest
??
FalseFalse
TrueTrueTestTest
conditionNconditionN
??
FalseFalse
Statement-NStatement-N
/* program to print the grade of student *//* program to print the grade of student */
int marks;int marks;
printf("Enter marks ? ");printf("Enter marks ? ");
scanf("%d", &marks);scanf("%d", &marks);
if(marks >= 75)if(marks >= 75)
printf("Distinction");printf("Distinction");
else if(marks >= 60)else if(marks >= 60)
printf("First class");printf("First class");
printf("Second class");printf("Second class");
printf("Third class");printf("Third class");
elseelse
printf("Failed");printf("Failed");
}}

switch statement :switch statement :
EntryEntry
switchswitch
expressionexpression
??
/* program to simulate a simple calculator *//* program to simulate a simple calculator */
float a,b;float a,b;
char opr;char opr;
printf("Enter number1 operator number2 : ");printf("Enter number1 operator number2 : ");
scanf("%f %c %f",&a,&opr,&b);scanf("%f %c %f",&a,&opr,&b);
switch(opr)switch(opr)
{{
case '+':case '+':
printf("Sum : %f",(a + b));printf("Sum : %f",(a + b));
break;break;
case '-':case '-':
printf("Difference : %f",(a - b));printf("Difference : %f",(a - b));
break;break;
case '*':case '*':
printf("Product : %f",(a * b));printf("Product : %f",(a * b));
break;break;
case '/':case '/':
printf("Quotient : %f",(a / b));printf("Quotient : %f",(a / b));
break;break;
default:default:
printf("Invalid Operation!");printf("Invalid Operation!");
}}
}}
associateassociate
statementstatement
associateassociate
statementstatement
associateassociate
statementstatement
associateassociate
statementstatement
value1value1 value2value2 valueNvalueN defaultdefault
ExitExit
…………......

Example
{{
int a,b;int a,b;
char choice;char choice;
printf("nInput 2 numbers:");printf("nInput 2 numbers:");
scanf("%d %d",&a,&b);scanf("%d %d",&a,&b);
printf("nEnter your choice:");printf("nEnter your choice:");
scanf("%c",&choice);scanf("%c",&choice);
switch(choice)switch(choice)
{{
case '+':case '+':
printf("nAddition:%d",(a+b));printf("nAddition:%d",(a+b));
break;break;
case '-':case '-':
printf("nSubtraction:%d",(a-b));printf("nSubtraction:%d",(a-b));
break;break;
default:default:
printf("nNo such choice available...");printf("nNo such choice available...");
break;break;
}}
return 0;return 0;
}}

?: - Conditional operator
#include<stdio.h>
int main()
{
int num;
printf("Enter the Number : ");
scanf("%d",&num);
flag = ((num%2==0)?1:0);
if(flag==0)
printf("nEven");
else
printf("nOdd");
}
#include<stdio.h>
int main()
{
int num;
printf("Enter the Number : ");
scanf("%d",&num);
(num%2==0)?printf("Even"):printf("Odd");
}
Syntax:
(Condition) ? stmt 1 : stmt 2

Loop Control/ Iterative
Statements
• while loop
• for loop
• do-while loop

Test
Condition
?
Body of The loop
False
truetrue
while – (Entry controlled )while – (Entry controlled )
EntryEntry
Loop StatementsLoop Statements
Following Statement
Test
Condition
?
Body of The loop
False
TrueTrue
EntryEntry
Following Statement
do-while – (Exit controlled )do-while – (Exit controlled )
/* sum of 1 to 10 numbers *//* sum of 1 to 10 numbers */
int i = 1,sum = 0;int i = 1,sum = 0;
while(i<=10){while(i<=10){
sum = sum + i;sum = sum + i;
i = i + 1;i = i + 1;
}}
printf(“Total : %d “,sum);printf(“Total : %d “,sum);
}}
/* average of 5 numbers *//* average of 5 numbers */
int count = 1;int count = 1;
float x, sum = 0;float x, sum = 0;
do {do {
printf(“x = “);printf(“x = “);
scanf(“%f”,&x);scanf(“%f”,&x);
sum += x;sum += x;
++ count;++ count;
} while(count <= 5);} while(count <= 5);
printf(“Average = %f “, (sum/5))printf(“Average = %f “, (sum/5))
}}

Do while example
{{
int n,i=1;int n,i=1;
int sum=0;int sum=0;
printf("n Enter N:");printf("n Enter N:");
scanf("%d",&n);scanf("%d",&n);
dodo
{{
sum=sum+i;sum=sum+i;
i++;i++;
} while(i<=10);} while(i<=10);
printf("n Sum of N natural number: %d", sum);printf("n Sum of N natural number: %d", sum);
return 0;return 0;
}}

for --for --
StatementStatement
Initialization Statement
Increment Statement
Test
Condition
?
Body of The loop
EntryEntry
TrueTrue
Following Statement
False
/* check whether a number is prime or not *//* check whether a number is prime or not */
int n,i,factors = 0;int n,i,factors = 0;
printf("Enter a number : ");printf("Enter a number : ");
for(i = 1; i <= n; i++) {for(i = 1; i <= n; i++) {
if((n % i)==0) ++factors;if((n % i)==0) ++factors;
}}
if (factors == 2)if (factors == 2)
printf("%d is prime number.",n);printf("%d is prime number.",n);
elseelse
printf("%d is not prime number.",n);printf("%d is not prime number.",n);
}}
{{
int n,i;int n,i;
int sum=0;int sum=0;
printf("n Enter N:");printf("n Enter N:");
for(i=1;i<=n;i++)for(i=1;i<=n;i++)
{{
sum=sum+i;sum=sum+i;
}}
printf("n Sum of N natural number: %d",printf("n Sum of N natural number: %d",
sum);sum);
return 0;return 0;
}}

Infinite for loop
• Syntax:
– for( ; ; )
• Example
{{
for(;;)for(;;)
{{
printf("n Hello");printf("n Hello");
}}
return 0;return 0;
}}
This program will print Hello infinite number of timesThis program will print Hello infinite number of times

Important Functions in math.h
abs(x) absolute value of integer x
ceil(x) rounds up and returns the smallest integer greater than or
equal to x
floor(x) rounds down and returns the largest integer less than or
equal to x
log(x) returns natural logarithm
pow(x,y) returns the value of xy
sqrt(x) returns square root of x
exp(x) returns natural anti logarithm
sin(x) returns sine value where x in radians
cos(x) returns cosine value where x in radians
tan(x) returns tangent values where x in radians
fmod(x,y) calculate x modulo y, where x and y are double
hypot(x,y) calculate hypotenuse of right angle where x,y are sides.
log10(x) returns logarithm base 10

Jump Statement
• break
• continue
• goto

break Statements
• break;
– break is used in terminating the loop
immediately after it is encountered

Example
/* C program to demonstrate the working of break statement by terminating a loop, if/* C program to demonstrate the working of break statement by terminating a loop, if
user inputs negative number*/user inputs negative number*/
# include <stdio.h># include <stdio.h>
int main(){int main(){
float num,average,sum=0;float num,average,sum=0;
int i,n;int i,n;
printf("Maximum no. of inputsn");printf("Maximum no. of inputsn");
for(i=1;i<=n;++i){for(i=1;i<=n;++i){
printf("Enter n%d: ",i);printf("Enter n%d: ",i);
scanf("%f",&num);scanf("%f",&num);
if(num<0.0)if(num<0.0)
break; //for loop breaks if num<0.0break; //for loop breaks if num<0.0
sum=sum+num;sum=sum+num;
}}
average=sum/(i-1);average=sum/(i-1);
printf("Average=%.2f",average);printf("Average=%.2f",average);
return 0;return 0;
}}

#include<stdio.h> int main() { int i; i = 0; while ( i < 20 ) { i++; continue; printf("Nothing to seen"); } return 0; }
{{
int i=0;int i=0;
while(i<20)while(i<20)
{{
i++;i++;
if (i==10)if (i==10)
break;break;
}}
printf("n%d",i);printf("n%d",i);
return 0;return 0;
}}

continue Statements
• continue;
– It is sometimes desirable to skip some
statements inside the loop. In such cases,
continue statements are used

Example
# include <stdio.h># include <stdio.h>
{{
int i,num,product;int i,num,product;
for(i=1,product=1;i<=4;++i)for(i=1,product=1;i<=4;++i)
{{
printf("Enter num%d:",i);printf("Enter num%d:",i);
scanf("%d",&num);scanf("%d",&num);
if(num==0)if(num==0)
continue; / *In this program, when num equals to zero, it skips the statement product*=numcontinue; / *In this program, when num equals to zero, it skips the statement product*=num
and continue the loop. */and continue the loop. */
product*=num;product*=num;
}}
printf("product=%d",product);printf("product=%d",product);
return 0;return 0;
}}
Output:Output: ??

Predict the output
#include<stdio.h> int main() { int i; i = 0; while ( i < 20 ) { i++; continue; printf("Nothing to seen"); } return 0; }
#include <stdio.h>
int main()
{
int i;
i = 0;
while ( i < 20 )
{
i++;
continue;
printf("Nothing to seen");
}
printf("n%d",i);
return 0;
}
Output:
?

{{
int i;int i;
for (i=1;i<=3;i++)for (i=1;i<=3;i++)
{{
MIT:MIT:
goto MITS;goto MITS;
}}
MITS: printf("n Hello...");MITS: printf("n Hello...");
goto MIT;goto MIT;
return 0;return 0;
}}
Output:Output:
Indefinitely prints “Hello…”Indefinitely prints “Hello…”

Example
{{
int age;int age;
Vote:Vote:
printf(“n you are eligible for voting");printf(“n you are eligible for voting");
NoVote:NoVote:
printf(“n you are not eligible to vote");printf(“n you are not eligible to vote");
printf(“n Enter you age:");printf(“n Enter you age:");
scanf("%d", &age);scanf("%d", &age);
if(age>=18)if(age>=18)
goto Vote;goto Vote;
elseelse
goto NoVote;goto NoVote;
return 0;return 0;
}}
Explanation:
•Vote and NoVote are labels.
•When the input is >= 18, the goto
statement is transferring the control to
label – Vote,
•Otherwise it transfers the control to
label-NoVote.
•This prints some unordered
outputs

{{
int age;int age;
printf("Enter you age:");printf("Enter you age:");
scanf("%d", &age);scanf("%d", &age);
if(age>=18)if(age>=18)
gotogoto Vote;Vote;
elseelse
gotogoto NoVote;NoVote;
Vote:Vote:
printf("you are eligible for voting");printf("you are eligible for voting");
gotogoto Exit;Exit;
NoVote:NoVote:
printf("you are not eligible to vote");printf("you are not eligible to vote");
gotogoto Exit;Exit;
Exit:Exit:
return 0;return 0;
}}
Explanation:
•Vote and NoVote are labels.
•When the input is >= 18, the goto statement i
transferring the control to label – Vote,
•Otherwise it transfers the control to label-
NoVote.
•This prints ordered outputs

exit() function
• C library function
• #include<stdlib.h>
• Terminates the calling process immediately
#include <stdio.h>
#include <stdlib.h>
int main ()
{
printf("Start of the program....n");
printf("Exiting the program....n");
exit(0);
printf("End of the program....n");
return 0;
}

Class room Exercise 1
• Program to find numbers between 100 and 150 evenly
divisible by 3 [Use for loop & if simple statement]
• Program to generate multiplication tables of user choice.
[use any loop]
• Program to find the biggest of three numbers. [use nested
if statement]
• Program to print the week name for an entered digit [For
instance, if 1 is entered as input, “Monday” should be
printed as output] [Use switch case statement]
• Program for conversion of upper case to lower case
alphabet [use ASCII logic]

• C program to Print all the even numbers between two
limits. (For instance, if the inputs r1=5, r2=34, output must
be 6, 8, 10, 12,…., 30,32,33)
• C Program to Check Vowel or consonant [Hint: use switch
case stmt or if statement]
• C program to print all the numbers divisible by 6 but not
multiple of 5 between two ranges.
• C Program to print N numbers in reverse order [For
instance, if input N=12, the output must be,
12,11,10,9,8,7,6,5,4,3,2,1]
• C Program to Display Fibonacci Sequence

• C program to find sum of odd numbers between two
ranges.
• C program to find sum of even numbers between two
ranges.
• C program to print the digits in words from 1 to 99. [use
switch case]

Example
//Upper to Lower case//Upper to Lower case
{{
char a,b;char a,b;
printf("n Enter a character:");printf("n Enter a character:");
scanf("%c",&a);scanf("%c",&a);
if(a>=65 && a<=90)if(a>=65 && a<=90)
b=a+32;b=a+32;
printf("n %c",b);printf("n %c",b);
return 0;return 0;
}}

Homework Exercises
• C Program to Check whether a given Number is Armstrong
• C Program to Check whether a given Number is Perfect Number
– A perfect number is a positive integer that is equal to the sum of
its proper positive divisors
• C Program to Print Armstrong Number from 1 to 1000
• C Program to Swap the Contents of two Numbers using Bitwise XOR
Operation

Perfect Number
#include <stdio.h>
int main()
{
int number, rem, sum = 0, i;
printf("Enter a Numbern");
scanf("%d", &number);
for (i = 1; i <= (number - 1); i++)
{
rem = number % i;
if (rem == 0)
{
sum = sum + i;
}
}
if (sum == number)
printf("Entered Number is perfect number");
else
printf("Entered Number is not a perfect number");
return 0;
}

Armstrong number
main()main()
{{
int number, temp, digit1, digit2, digit3;int number, temp, digit1, digit2, digit3;
printf("Print all Armstrong numbers between 1 and 1000:n");printf("Print all Armstrong numbers between 1 and 1000:n");
number = 001;number = 001;
while (number <= 900)while (number <= 900)
{{
digit1 = number - ((number / 10) * 10);digit1 = number - ((number / 10) * 10);
digit2 = (number / 10) - ((number / 100) * 10);digit2 = (number / 10) - ((number / 100) * 10);
digit3 = (number / 100) - ((number / 1000) * 10);digit3 = (number / 100) - ((number / 1000) * 10);
temp = (digit1 * digit1 * digit1) + (digit2 * digit2 * digit2) + (digit3 * digit3 * digit3);temp = (digit1 * digit1 * digit1) + (digit2 * digit2 * digit2) + (digit3 * digit3 * digit3);
if (temp == number)if (temp == number)
{{
printf("n Armstrong no is:%d", temp);printf("n Armstrong no is:%d", temp);
}}
number++;number++;
}}
}}

Swapping Binary number using
XOR operator
void main()void main()
{{
long i, k;long i, k;
printf("Enter two integers n");printf("Enter two integers n");
scanf("%ld %ld", &i, &k);scanf("%ld %ld", &i, &k);
printf("n Before swapping i= %ld and k = %ld", i, k);printf("n Before swapping i= %ld and k = %ld", i, k);
i = i ^ k;i = i ^ k;
k = i ^ k;k = i ^ k;
i = i ^ k;i = i ^ k;
printf("n After swapping i= %ld and k = %ld", i, k);printf("n After swapping i= %ld and k = %ld", i, k);
}}

Unit 1 c - all topics

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Unit 1 c - all topics