#include<iostream>
using namespace std;
void zhuanhuan1(int x,int y);
void zhuanhuan2(int& x,int& y);
int main()
{
    int a=10;
    int b=20;
    zhuanhuan1(a,b);
    cout<<a<<endl;
    cout<<b<<endl;
     zhuanhuan2(a,b);
    cout<<a<<endl;
    cout<<b<<endl;
        return 0;
    }
void zhuanhuan1(int x,int y)
{
     int temp=x;
     x=y;
     y=temp;
     }
void zhuanhuan2(int& x,int& y)
{
     int temp=x;
     x=y;
     y=temp;
     }
为什么在zhuanhuan1中，输出a,b的值不发生变化！