// Example 5-5：交換兩個整形變量的值
#include <iostream.h>
void swap(int &x,int &y)
{
	int tmp = x;
	x   = y;
	y   = tmp;
}
// 測試函數 swap() 用的主函數
void main()
{
	int a = 1,b = 2;
	cout << "Before exchange：a= " << a << "，b= " << b << endl;
	swap(a,b);
	cout << "After  exchange：a= " << a << "，b= " << b << endl;
}