#include <iostream>
using namespace std;
int main(void)
{
int x = 3;
int &y=x;//定義引用，y是x的引用
cout<<x<<","<<y<<endl;//打印x和y的值
//修改y的值
y = 5;
//再次打印x和y的值
cout<<x<<","<<y<<endl;
return 0;
}
