Cpp-learning/函数1/3、值传递.cpp

#include <iostream>

//所谓值传递，就是函数调用时实参将数值传递给形参
//值传递时，如果形参发生，并不会影响实参

//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
#if(0)
void swap(int num1, int num2)
{
	std::cout << "交换前的数字是：" << std::endl;
	std::cout << "num1 = " << num1 << std::endl;
	std::cout << "num2 = " << num2 << std::endl;

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

	std::cout << "交换后的数字是：" << std::endl;
	std::cout << "num1 = " << num1 << std::endl;
	std::cout << "num2 = " << num2 << std::endl;

	//return;    无返回值或不需要返回值的时候，可以不写return
}

int main3()
{
	int a = 10;
	int b = 20;

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

	//当我们做值传递的时候，函数的形参发生变化，并不会影响实参
	swap(a, b);

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

	system("pause");

	return 0;
}
#endif