pubpriv.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 54 行

// pubpriv.cpp
// tests publicly- and privately-derived classes
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class A                  //base class
   {
   private:
      int privdataA;     //(functions have the same access
   protected:            //rules as the data shown here)
      int protdataA;
   public:
      int pubdataA;
   };
////////////////////////////////////////////////////////////////
class B : public A       //publicly-derived class
   {
   public:
      void funct()
         {
         int a;
         a = privdataA;  //error: not accessible
         a = protdataA;  //OK
         a = pubdataA;   //OK
         }
   };
////////////////////////////////////////////////////////////////
class C : private A      //privately-derived class
   {
   public:
      void funct()
         {
         int a;
         a = privdataA;  //error: not accessible
         a = protdataA;  //OK
         a = pubdataA;   //OK
         }
   };
////////////////////////////////////////////////////////////////
int main()
   {
   int a;

   B objB;
   a = objB.privdataA;   //error: not accessible
   a = objB.protdataA;   //error: not accessible
   a = objB.pubdataA;    //OK (A public to B)

   C objC;
   a = objC.privdataA;   //error: not accessible
   a = objC.protdataA;   //error: not accessible
   a = objC.pubdataA;    //error: not accessible (A private to C)
   return 0;
   }