学步园

【题目】宏#define命令练习(2)

#include<stdio.h>
#define exchange(a,b) { int t;t=a;a=b;b=t;}//注意放在一行里
int main()
{
	int x=10;
	int y=20;
	printf("x=%d; y=%d\n",x,y);
	exchange(x,y);
	printf("x=%d; y=%d\n",x,y);
	return 0;
}