Why it show output is 28 please explain any one

Question

#include <stdio.h>
#define square(x) x*x
int main() {
int i=(28/square(4));
printf("%d",i);
return 0;
}

Answer 1

Just for saftey, when declaring macros use parenthesis around the variables and around the whole thing if it helps:

#define square(x) x*x
/* to */
#define square(x) ((x)*(x))

a bit excessive, but it turns:

int i = 28/4*4;
/* into */
int i = 28/((4)*(4));

Answer 2

square() is a marco, not a function, so

28/square(4) = 28/4*4 = 6*4 = 24.