list1410.cpp

teach yourself C++ in 21 days 第五版

// Listing 14.10
// Deriving ADTs from other ADTs
#include <iostream>
using namespace std;

enum COLOR { Red, Green, Blue, Yellow, White, Black, Brown } ;

class Animal        // common base to both Mammal and Fish
{
  public:
    Animal(int);
    virtual ~Animal() { cout << "Animal destructor...\n"; }
    virtual int GetAge() const { return itsAge; }
    virtual void SetAge(int age) { itsAge = age; }
    virtual void Sleep() const = 0;
    virtual void Eat() const = 0;
    virtual void Reproduce() const = 0;
    virtual void Move() const = 0;
    virtual void Speak() const = 0;
  private:
    int itsAge;
};

Animal::Animal(int age):
itsAge(age)
{
   cout << "Animal constructor...\n";
}

class Mammal : public Animal
{
  public:
    Mammal(int age):Animal(age)
      { cout << "Mammal constructor...\n";}
    virtual ~Mammal() { cout << "Mammal destructor...\n";}
    virtual void Reproduce() const
      { cout << "Mammal reproduction depicted...\n"; }
};

class Fish : public Animal
{
  public:
    Fish(int age):Animal(age)
      { cout << "Fish constructor...\n";}
    virtual ~Fish() {cout << "Fish destructor...\n";  }
    virtual void Sleep() const { cout << "fish snoring...\n"; }
    virtual void Eat() const { cout << "fish feeding...\n"; }
    virtual void Reproduce() const
      { cout << "fish laying eggs...\n"; }
    virtual void Move() const
      { cout << "fish swimming...\n";   }
    virtual void Speak() const { }
};

class Horse : public Mammal
{
  public:
    Horse(int age, COLOR color ):
    Mammal(age), itsColor(color)
      { cout << "Horse constructor...\n"; }
    virtual ~Horse() { cout << "Horse destructor...\n"; }
    virtual void Speak()const { cout << "Whinny!... \n"; }
    virtual COLOR GetItsColor() const { return itsColor; }
    virtual void Sleep() const
      { cout << "Horse snoring...\n"; }
    virtual void Eat() const { cout << "Horse feeding...\n"; }
    virtual void Move() const { cout << "Horse running...\n";}

  protected:
    COLOR itsColor;
};

class Dog : public Mammal
{
  public:
    Dog(int age, COLOR color ):
    Mammal(age), itsColor(color)
       { cout << "Dog constructor...\n"; }
    virtual ~Dog() { cout << "Dog destructor...\n"; }
    virtual void Speak()const { cout << "Whoof!... \n"; }
    virtual void Sleep() const { cout << "Dog snoring...\n"; }
    virtual void Eat() const { cout << "Dog eating...\n"; }
    virtual void Move() const  { cout << "Dog running...\n"; }
    virtual void Reproduce() const
      { cout << "Dogs reproducing...\n"; }

  protected:
    COLOR itsColor;
};

int main()
{
   Animal *pAnimal=0;
   int choice;
   bool fQuit = false;

   while (fQuit == false)
   {
      cout << "(1)Dog (2)Horse (3)Fish (0)Quit: ";
      cin >> choice;
 
      switch (choice)
      {
         case 1: pAnimal = new Dog(5,Brown);
                 break;
         case 2: pAnimal = new Horse(4,Black);
                 break;
         case 3: pAnimal = new Fish (5);
                 break;
        default: fQuit = true;
                 break;
       }
       if (fQuit == false)
       {   
          pAnimal->Speak();
          pAnimal->Eat();
          pAnimal->Reproduce();
          pAnimal->Move();
          pAnimal->Sleep();
          delete pAnimal;
          cout << endl;
       }  
    }
    return 0;
 }