Unit ii ppt

PREPARED BY K,NITHIYA
AP/IT
ANNAI CLG OF ENGG

CHARACTER SET
C CHARACTER SET
Execution Character
Set
Source Character Set
DigitsAlphabets Special Character
White
Space
Character
Space
Escape
Sequence
AP/IT
ANNAI CLG OF ENGG

A Character denotes an alphabet, digit or a
special character.
Lowercase Letters – A,B,C….. Z
Uppercase Letters - a,b,c…… z
Digits – 0,1,2,3,…7,8,9
+ Plus Sign - Minus Sign , Comma
* Asterisk / Slash = Equal to
@ At Symbol < Less Than : Colon
; Semicolon
AP/IT
ANNAI CLG OF ENGG

It will work at the execution time only and it cannot be printed.
It always represented by a backslash() followed by a character.
AP/IT
ANNAI CLG OF ENGG

 The smallest individual units of a c program are
known as tokens
 It can be categorized into following ways
C tokens
operators
Special
symbolstringconstantsIdentifiersKeywords
AP/IT
ANNAI CLG OF ENGG

 Keyword is a reserved keyword that has a particular meaning
 It should be in lower case
 There are 32 keywords in c language
S.
NO
keyword S.
NO
keyword S.NO keyword S.
NO
keyword keyword
1 auto 8 do 15 goto 22 signed 29.unsigned
2 break 9 double 16 if 23 sizeof 30.void
3 case 10 else 17 int 24 static 31.volatile
4 char 11 enum 18 long 25 struct 32.while
5 const 12 extern 19 register 26 switch
6 continue 13 float 20 return 27 typedef
7 default 14 for 21 short 28 union
AP/IT
ANNAI CLG OF ENGG

 It can be a variable name and function name etc.
 Maximum length of an identifier is 31
 Special character are not allowed except(_).
Valid invalid
nithiya Nithya#
NITHIYA Nith ya ->blank space
Nithya3 Auto
Nithya 3nithya
AP/IT
ANNAI CLG OF ENGG

10
-356
4600.5
-0.963
‘A’
‘*’
“A”
“CSC”
AP/IT
ANNAI CLG OF ENGG

Variables are named locations in memory that are used to
hold a value that may be modified by the program.
K5.ico ANIMATAY006.ICO
The syntax for declaring a variable is
Data type Variablename;
Valid Examples :
CSC avg_val
m1 Chennai Anu
mark_1
AP/IT
ANNAI CLG OF ENGG

RULES for framing a variable :
The first character in the Variable name must be an alphabet
Alphabets can be followed by a number of digits or
underscores
No commas or Blank spaces are allowed within a variable
name
No Special character other than Underscore(_) can be used in
a variable name.
The variable name should not be a keyword
Variable names are case sensitive
It should not be of length more than 31 characters
AP/IT
ANNAI CLG OF ENGG

INTIALIZING VARIABLE
Assigning some value to the variable is known as intialization
SYNTAX:
Data type variable name=value;
Example
Int a=10;
SCOPE OF VARIABLE
1.Local variable
2.Global variable
AP/IT
ANNAI CLG OF ENGG

Scope of
variable
definition example
Local
variable
Declared
inside the
block
main()
{
Int a=8; // local
variable
}
Global
variable
Declared
before the
main function
Int a=8;
Main()
{
//no of statement
}
AP/IT
ANNAI CLG OF ENGG

C data types
Empty data
type
User defined
data type
Derived or
secondary data
type
Primary data
type
AP/IT
ANNAI CLG OF ENGG
PRIMARY DATA TYPES
int float chardouble
1.PRIMARY DATA TYPES

S.N
O
Data
Type
Explanation Size(bytes) CONTRO
L
STRING
RANGE SYNTAX EXAMPLE
1 int It store numeric values
without decimal point
Example:9,10,23
2 bytes %d or %i -32,768 to
+32,767
int
Variable_na
me;
int roll_no;
2 float It store the numeric
values with decimal
point
Example:3.12,47.098
4 bytes %f or %g 3.4E-38 to
3.4E+38
Float
Variable_na
me;
float a;
3 double It store the big number
of decimal point
Example:2.13455
8 bytes %if 1.7E-308 to
1.7E+308
Double
Variable
name;
double b;
4 char It store the single
character
Example:’a’,’9’
1 bytes %c -128 to +127 Char
Variable
name;
char
a=“nithiya”;
AP/IT
ANNAI CLG OF ENGG

1.Array
An array is a collection of variable of same data type
SYNTAX: Datatype array_name[array size];
Example: int a[10];
2.Structures
it stores the multiple values of same or different data type
under a single name
Syntax:
Struct <struct name>
{
Member 1;member 2;};
DERIVED DATA
TYPE
array pointersunionsstructures

EXAMPLE:
Struct Student
{
Char name[10];
Int roll_no;
};
3.UNION
A union is store the multiple values of same or different data type
SYNTAX:
union <union name>
{
Member 1; member 2;
}
EXAMPLE:
Union student
{
Char name[25];
};
AP/IT
ANNAI CLG OF ENGG

4.POINTERS
A pointer is holds the memory address of another variable
SYNTAX:
Data type *variable name
EXAMPLE : int *a
EMPTY DATA TYPE
i)Void
its represents an empty value
AP/IT
ANNAI CLG OF ENGG

1.Type Definition
Example: Typedef int age;
age male,female
2.Enumerated Datatype
Example :
enum mon{jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec };
AP/IT
ANNAI CLG OF ENGG
USER DEFINED DATA TYPE

Control
statement
conditional unconditional
selective looping
Nested if else
Simple if
If else
If-else if
ladder
Switch case
while
do while
for
goto
break
continue
AP/IT
ANNAI CLG OF ENGG

 A program is a sequence of one or more instructions
 The condition will check whether the particular
condition are true (or) not.
 1.SIMPLE IF STATEMENT
 If the condition is true the set of statements are
executed
 SYNTAX

if(condition)
{
Statement 1;
}
AP/IT
ANNAI CLG OF ENGG

To find the given no is even or odd
#include<stdio.h>
#include<conio.h>
main()
{
int no;
clrscr();
printf(“n Enter the number”);
scanf(“%d”,&no);
if(no%2==0)
{
printf(The given no is even”);
}}
Output
Enter the number
24
The given no is even
AP/IT
ANNAI CLG OF ENGG

2.if else statement
It is a two way decision making statement
SYNTAX:
if(condition)
{
Statement 1;
}
else
{ false statement;
}
#include<stdio.h>
#include<conio.h>
main()
{
int no;
clrscr();
if(no%2==0)
{
}
else
{
Printf(“The given no is odd”);
}
#include<stdio.h>
#include<conio.h>
main()
{
int no;
clrscr();
if(no%2==0)
{
}
else
{
Printf(“The given no is odd”);
}
Output
Enter the number
25
The given no is odd
AP/IT
ANNAI CLG OF ENGG

 The number of logical conditions is checked for executing various
statements
 SYNTAX
 if(condition 1)
 {
 True statement 1;
 }
 else
 {
 if(condition 2)
 {
 True statement 2;
 }
 else
 {
 False statement
}}
#include<stdio.h>
#include<conio.h>
Main()
{
int a,b,c;
clrscr();
printf(“Enter a,b,c”);
scanf(“%d%d%d”,&a,&b,&c);
if((a>b)&&(a>c))
{
printf(“A is greater”);
}
else
{
If(b>c)
{
printf(“B is greater”);
}
else
{
printf(“C is greater”);
}}}
Output
Enter the values of a,b,c
4
2
3
A is greater

Nested if-else can be chained with one another
Syntax:
if(condition 1)
{
Statement 1;
}
else if(condition 2);
{
Statement 2;
}
else if(condition 3)
{
statement;
}
else
{
Final statement
}
#include<stdio.h>
#include<conio.h>
Main()
{
int a,b,c;
clrscr();
printf(“Enter a,b,c”);
scanf(“%d%d%d”,&a,&b,&c);
if(a>b)
{
If(a>c)
{
printf(“A is greater”);
}
else
{
} }
else if(b>c)
{
printf(“B is greater”);
}
else
{
}}
Output
Enter the values of a,b,c
4
2
3
A is greater
AP/IT
ANNAI CLG OF ENGG

 If the value matches with case constant, this particular case statement is executed.
if not default is executed.
 SYNTAX:
 Switch (variable)
 {
 Case constant 1:
 statement 1;
 Break;
 Case constant 2:
 Statement 2;
 Break;
 ..
 ..
 default:
 Default statement;
 }
#include<stdio.h>
#include<conio.h>
Main()
{
int a=10,b=5;
char symbol;
clrscr();
printf(“Enter the symbol”);
scanf(“%c”,&symbol);
switch(symbol)
{
case’+’:
result=a+b;
break;
case’-’:
result=a-b;
break;
case’*’:
Result=a*b;
Break;
Case’/’:
Result=a/b;
break;
case’%’:
Result=a%b;
break;
}
Default:
Printf(“invalid symbol”);
}
Printf(“the result is %d”,result);
}
Output
Enter the symbol:+
The result is 15
Enter the symbol:%
The result is 0
AP/IT
ANNAI CLG OF ENGG

Unit ii ppt

More Related Content

What's hot (20)

Similar to Unit ii ppt (20)

More from ANJALAI AMMAL MAHALINGAM ENGINEERING COLLEGE (9)

Recently uploaded (20)

Unit ii ppt