C Programming
Constants in C
A constant variable is such type of variable that's value can't be changed during execution of the program.
Constants in C
| Constant | Example |
|---|
| Decimal Constant | 10, 20, 450 etc. |
| Real or Floating-point Constant | 10.3, 20.2, 450.6 etc. |
| Octal Constant | 021, 033, 046 etc. |
| Hexadecimal Constant | 0x2a, 0x7b, 0xaa etc. |
| Character Constant | 'a', 'b', 'x' etc. |
| String Constant | "c", "c program", "c in javatpoint" etc. |
Example
void main()
{
const int a=10;
printf("%d", a);
a=a+10; // Value of "a" cannot be changed.
}
O/p.- Compile Error.
We can define constant with two different mechanism-
1. Variable Constant
2. Symbolic Constant
Variable Constant
If any declare any variable with const keyword is called variable constant.
#include <stdio.h>
#include <conio.h>
void main()
{
const int a=10;
printf("Constant value %d", a);
}
O/p: Constant value 10
C Symbolic Constant or #define preprocessor
The variable which is defined with the help of # define preprocessor is called symbolic constant.
#include <stdio.h>
#define PI 3.14
void main()
{
printf("Value of PI is=%f",PI);
}
O/p: Value of PI is= 3.14
June 23, 2017
