#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>

#include<string.h>

void swap2(int* pa, int* pb)

{

int tmp = 0;

tmp = *pa;

*pa = *pb;

*pb = tmp;

}

int main()

{

int a = 10;

int b = 20;

//int tmp = 0;

printf("a=%d  b=%d\n", a, b);

//swap1(a, b);//不需要返回，所以没返回值，就是交换一下

swap2(&a, &b);

printf("a=%d  b=%d\n", a, b);

return 0;

}