#include <iostream>
using namespace std;

//值传递
//定义函数，实现两个数字进行交换函数
//如果函数不需要返回值，声明的时候可以写void;

void swap(int num1, int num2)
{
    cout << "交换前:" << endl;
    cout << num1 << endl;
    cout << num2 << endl;

    int temp = num1;
    num1 = num2;
    num2 = temp;


    cout << "交换后:" << endl;
    cout << num1 << endl;
    cout << num2 << endl;
    //return;//返回值不需要时可以不写
}


int main()
{
    int a = 10;
    int b = 20;
    cout << "a=" << a << endl;
    cout << "b=" << b << endl;
    //函数的形参发生改变，并不影响实参
    swap(a, b);
    cout << "a=" << a << endl;
    cout << "b=" << b << endl;
    system("pause");
    return 0;
}