宏#define命令练习2

#include<stdio.h>#define exchange(a,b) {int c;c=a;a=b;b=c;}int main(){int x=10;int y=20;printf("原数据:");printf("x=%d,y=%d\n",x,y);exchange(x,y);printf("交换后:");printf("x=%d,y=%d\n",x,y);return 0;}