用函数交换a与b的值

#define _CRT_SECURE_NO_WARNINGS 1
#include 
void swap(int* pa, int* pb)//void 表示不返回值，如果要return什么，去掉void
{
	int z;
	z = *pa;
	*pa = *pb;
	*pb = z;
}
int main()
{
	int a = 10;
	int b = 20;
	printf("原来是：a=%d b=%d\n", a, b);
	swap(&a, &b);
	printf("现在是：a=%d b=%d", a, b);
	return 0;
}

 

#define _CRT_SECURE_NO_WARNINGS 1
#include 
void swap(int x, int y)
{int z = 0;;
z = x;
x = y;
y = z;
}
int main()
{
	int a = 10;
	int b = 20;
	printf("原来是：a=%d b=%d\n", a, b);
	swap(a, b);
	printf("现在是：a=%d b=%d", a, b);
	return 0;
}