Macro with argument

#define can be used to write macro definitions with parameters.

Syntax :

#define identifier(identifier 1,.....identifier n) token_string

Token string: is optional but used in every case.

Example :

#include <stdio.h>
#define PI 3.1415
#define area(r) (PI*(r)*(r))
int main()
{
    int radius;
    float area;
    printf("Enter the radius : ");
    scanf("%d",&radius);

    area=area(radius);
    printf("\nArea=%.2f",area);
    return 0;
}

Output :

Enter the radius :
Area=12.57

Explanation :

Every time the program encounters area(radius), it will be replace by (3.1415*(r)*(r)).