C programming

Question

I'm not able to understand how literal substitution will work while running this code?

#define CALC(X) (X*X)
int main() {
int a, b=5;
a = CALC(b+2);
printf("\n a= %d b=%d", a,b);
}

Answer 1

Output is a=17 and b=5;

first of all i will explain you that "The macro arguments are not evaluated before macro expansion. "

so when we pass the argument to this macro it will look like

b=5;

so a=CALC(5+2)// the macro calculate5+2*5+2

so a=17;

and the value of b will unchanged.