【C++】引用变量--2.将引用作为函数参数

目录

按值传递和按引用传递区别 

指针，引用传递程序示例

程序理解

按值传递和按引用传递区别 

指针，引用传递程序示例

      // swaps.cpp -- 使用指针和引用来进行交换
      #include<iostream>
      void swapr(int & a, int & b);
      void swapp(int * p, int * q);
      void swapv(int a, int b);
      int main()
      {
     	using namespace std;
     	int wallet1 = 300;
     	int wallet2 = 350;
     	cout << "--------------------" << endl;
     	cout << "wallet1 = $" << wallet1;
     	cout << "wallet2 = $" << wallet2 << endl << endl;
     	cout << "--------------------" << endl;
     	cout << "Using references to swap contents: \n";
      	swapr(wallet1, wallet2);
     	cout << "wallet1 = $" << wallet1;
     	cout << "wallet2 = $" << wallet2 << endl << endl;
     	cout << "--------------------" << endl;
     	cout << "Using pointer to swap contents again:\n";
      	swapp(&wallet1, &wallet2);
     	cout << "wallet1 = $" << wallet1;
     	cout << "wallet2 = $" << wallet2 << endl << endl;
     	cout << "--------------------" << endl;
     	cout << "Trying to use passing by value：\n";
      	swapv(wallet1, wallet2);
     	cout << "wallet1 = $" << wallet1;
     	cout << "wallet2 = $" << wallet2 << endl << endl;
     	return 0;
      }
      void swapr(int & a, int & b)//使用引用
      {
     	int temp;
      	temp = a;
      	a = b;
      	b = temp;
      }
      void swapp(int * p, int * q)
      {
     	int temp;
      	temp = *p;
      	*p = *q;
      	*q = temp;
      }
      void swapv(int a, int b)
      {
     	int temp;
      	temp = a;
      	a = b;
      	b = temp;
      }
  
 

程序理解

按引用传递swapr(wallet1, wallet2)和按值传递swapv(wallet1, wallet2)看起来相同，只有通过原型才知道是按值传递还是按引用传递

文章来源: kings.blog.csdn.net，作者：人工智能博士，版权归原作者所有，如需转载，请联系作者。

原文链接：kings.blog.csdn.net/article/details/90452105