assign.cpp

来自「本课程主要介绍面向对象程序设计的方法和c++语言的基本概念。以c++语言中的面向」· C++ 代码 · 共 37 行

// assign.cpp
// overloads assignment operator (=)
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class alpha
   {
   private:
      int data;
   public:
      alpha()                      //no-arg constructor
         { }
      alpha(int d)                 //one-arg constructor
         { data = d; }
      void display()               //display data
         { cout << data; }
      alpha operator = (alpha& a)  //overloaded = operator
         {
         data = a.data;            //not done automatically
         cout << "\nAssignment operator invoked";
         return alpha(data);       //return copy of this alpha
         }
   };
////////////////////////////////////////////////////////////////
int main()
   {
   alpha a1(37);
   alpha a2;

   a2 = a1;                        //invoke overloaded =
   cout << "\na2="; a2.display();  //display a2

   alpha a3 = a2;                  //does NOT invoke =
   cout << "\na3="; a3.display();  //display a3
   cout << endl;
   return 0;
   }