PLUS(m1, m2)*MINUS(m2, m1);

Question

為什麼算出來是25而不是8*2=16?
#define PLUS(a, b) a+b
#define MINUS(a, b) a-b
#include <stdio.h>
#include <stdlib.h>
main()
{ int m1 = 3, m2 = 5;
m1 = PLUS(m1, m2)*MINUS(m2, m1);
printf("%d\n", m1);
system("pause");

}

Answer 1

Macro跟副程式不太一樣!!

m1 = PLUS(m1, m2)*MINUS(m2, m1);
解析為
m1=m1+m2*m2-m1

m1=3+5*5-3=25