why the output is 7??

Question

her's the code :
#include <stdio.h>
#define sqr(x) x*x
int main() {
printf ("%d",sqr(3+1));
return 0;
}
the output was 7,why it's not 16?

Answer 1

sqr(x) is x*x
so sqr(3+1) is 3+1*3+1
you can do the math

Answer 2

Because your sqr(x) x*x translates to 3+1*3+1. To get 16 you have to put x in parenthises like: #define sqr(x) (x)*(x), which will be translated to (3+1)*(3+1).
See: https://code.sololearn.com/cgDbTQlct1DD/#