Defining Constants
There are two simple ways in C to define constants −
-> Using #define preprocessor.
-> Using const keyword.
For Example:
For Example:
#include<stdio.h>
#define HEIGHT 20
#define WIDTH 30
#define FILE_NAME "config.txt"
void main()
{
const int height = 20;
const int width = 30;
const char name[] = "SAROJ";
const char file_name[] = "config.txt";
printf("Height : %d",HEIGHT);
printf("WIDTH : %d",WIDTH);
printf("FILE_NAME : %s",FILE_NAME);
}
Here in this program, constant is declared in two ways, one is by using preprocessor directive called #define and another is like normal variable declaration but const keyword is used in front of it. Also note that, In C programming language, the constant name is always written in capital letter.
