list1403.cpp

teach yourself C++ in 21 days 第五版

// Listing 14.3. Multiple inheritance.

#include <iostream>
using std::cout;
using std::cin;
using std::endl;

class Horse
{
  public:
    Horse() { cout << "Horse constructor... "; }
    virtual ~Horse() { cout << "Horse destructor... "; }
    virtual void Whinny() const { cout << "Whinny!... "; }
  private:
    int itsAge;
};

class Bird
{
  public:
    Bird() { cout << "Bird constructor... "; }
    virtual ~Bird() { cout << "Bird destructor... "; }
    virtual void Chirp() const { cout << "Chirp... ";  }
    virtual void Fly() const
    {
       cout << "I can fly! I can fly! I can fly! ";
    }
  private:
    int itsWeight;
};

class Pegasus : public Horse, public Bird
{
  public:
    void Chirp() const { Whinny(); }
    Pegasus() { cout << "Pegasus constructor... "; }
    ~Pegasus() { cout << "Pegasus destructor...  "; }
};

const int MagicNumber = 2;
int main()
{
   Horse* Ranch[MagicNumber];
   Bird* Aviary[MagicNumber];
   Horse * pHorse;
   Bird * pBird;
   int choice,i;
   for (i=0; i<MagicNumber; i++)
   {
      cout << "\n(1)Horse (2)Pegasus: ";
      cin >> choice;
      if (choice == 2)
         pHorse = new Pegasus;
      else
         pHorse = new Horse;
      Ranch[i] = pHorse;
   }
   for (i=0; i<MagicNumber; i++)
   {
      cout << "\n(1)Bird (2)Pegasus: ";
      cin >> choice;
      if (choice == 2)
         pBird = new Pegasus;
      else
         pBird = new Bird;
      Aviary[i] = pBird;
   }

   cout << endl;
   for (i=0; i<MagicNumber; i++)
   {
      cout << "\nRanch[" << i << "]: " ;
      Ranch[i]->Whinny();
      delete Ranch[i];
   }

   for (i=0; i<MagicNumber; i++)
   {
      cout << "\nAviary[" << i << "]: " ;
      Aviary[i]->Chirp();
      Aviary[i]->Fly();
      delete Aviary[i];
   }
   return 0;
}