函数间的参数传递

函数间的参数传递

值调用：

//交换两个变量的值（不成功）
#include<iostream>
using namespace std;
void myswap(int x, int y)
{
    int tmp = x;
    x = y;
    y = tmp;
}
int main()
{
    int a = 2, b = 3;
    cout<<"Before exchange : a = "<<a<<", b = "<<b<<endl;
    myswap(a, b);
    cout<<"After exchange  : a = "<<a<<", b = "<<b<<endl;
    return 0;
}

引用调用：

//交换两个变量的值(成功）
#include<iostream>
using namespace std;
void myswap(int &x, int &y)
{
    int tmp = x;
    x = y;
    y = tmp;
}
int main()
{
    int a = 2, b = 3;
    cout<<"Before exchange : a = "<<a<<",b = "<<b<<endl;
    myswap(a, b);
    cout<<"After exchange  : a = "<<a<<",b = "<<b<<endl;
    return 0;
}

地址调用：

//交换两个变量的值(成功）
#include<iostream>
using namespace std;
void myswap(int *x, int *y)
{
    int temp = *x;
    *x = *y;
    *y = temp;
}
int main()
{
    int a = 2, b = 3;
    cout<<"Before exchange : a = "<<a<<",b = "<<b<<endl;
    myswap(&a, &b);
    cout<<"After exchange  : a = "<<a<<",b = "<<b<<endl;
    return 0;
}