【C++】值传递

函数值传递的特点：值传递过程中即使形参改变也不会改变实参

没有返回值的函数用" void "定义

下面是一个实例：

#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，声明可以写成void
void swap(int num1, int num2)
{
	cout << "交换前：" << endl;
	cout << "num1 = " << num1 << endl;
	cout << "num2 = " << num2 << endl;

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

	cout << "交换后：" << endl;
	cout << "num1 = " << num1 << endl;
	cout << "num2 = " << num2 << endl;

	//return; 函数不需要返回值的时候可以不写return
}

int main() {

	int a = 10;
	int b = 20;

	cout << "a = " << a << endl;
	cout << "b = " << b << endl;

	//当我们做值传递的时候，函数的形参发生任何改变不会影响实参
	swap(a, b);

	cout << "a = " << a << endl;
	cout << "b = " << b << endl;

	system("pause");

	return 0;

}

输出结果为