【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