The variable is an arbitrary name that is used to name a value or define a value .It is also named as an identifier
EG:….. a=5 ==> here is the a is variable and 5 is the value of a
RULES FOR DECLARING VARIABLE:
- the n number of variables can be declared in single line
- after each variable the must be a separation operator
- there must not be any space between a single variable declaration
- only the underscore symbol which can be used in -between or in front of a single variable as _a or int a_b;
- the variable must begin with an alphabet .
CONSTANTS:
constant is a variable which contains the value that cannot be changed till the execution of the program.
eg: const int a=5;
DATA TYPES:
there are some types of data type are as follows :
- integer
- floating point
- character
- string
INTEGER :
integer is the data type which contains the value like 2 4 6 5 7 2 etc…
the size of an integer is 2 bytes..
INTEGER TYPES:
- int == 2 bytes
- shortint == 2 bytes
- signed int == 2 bytes
- long int == 4 bytes
- unsigned int == 2 bytes
- unsigned long int== 4 bytes
EG PROGRAM FOR INT:
/*ADDITION OF TWO NUMBER USING INTEGER */
#include<stdio.h>
#include<conio.h>
void main()
{
int a,b,c;
clrscr();
printf(” enter a & b values:);
scanf(“%d%d”,&a,&b);
c = a+b;
printf(“\n c=%d”,c);
getch();
}
OUTPUT:
enter a & b the value:
2
3
c=5
FLOATING POINT :
float is the type which contains the value like 2.0,3.5,5.5 etc………….
FLOAT TYPES :
- float == 4 bytes
- double == 8 bytes
- long double == 10 bytes
EG PROGRAM FOR FLOAT :
/*addition of two numbers using float */
#include<stdio.h>
#include<conio.h>
void main()
{
float a,b,c;
clrscr();
c=a+b;
printf(“\n c=%f “,c);
getch();
}
OUTPUT:
3.5+5.4=8.9
CHARACTER TYPE:
char is the type which contains the value like ‘a’ , ‘@’ ,’$’,etc..
CHAR TYPES:
- char == 1 bytes
- string char == assigned size bytes
EG PROGRAM FOR CHAR:
/*using char*/
#include<stdio.h>
#include<conio.h>
void main()
{
char a;
clrscr();
printf(” enter a character value”);
scanf(“%c”,&a);
printf(“a=%c”,a);
getch();
}
OUTPUT:
enter a value :
g
a=g
STRING TYPE:
the string is that consists of values of set of characters..
EG PROGRAM FOR STRING CHARACTER:
/*using string char*/
#include<stdio.h>
#include<conio.h>
void main()
{
char a[20];
clrscr();
printf(“enter a character value:);
scanf(“%s”,&a);
printf(“\n a=%s”,a);
getch();
}
OUTPUT:
enter the a value: sivaram
sivaram
MASK INVENTERS 