Complex Hierarchies of Abstraction - C++ Class

C++ examples for Class:Virtual Function

  1. HOME
  2. C++
  3. Class
  4. Virtual Function

Description

Complex Hierarchies of Abstraction

Demo Code

                                                                       
#include <iostream> 
                                                                        
enum COLOR { Red, Green, Blue, Yellow, White, Black, Brown } ; 
                                                                        
class Animal // common base to both horse and bird 
{ 
public: /*w w w  . j  av  a  2s .co  m*/
    Animal(int); 
    virtual ~Animal() { std::cout << "Animal destructor ...\n"; } 
    virtual int getAge() const { return age; } 
    virtual void setAge(int newAge) { age = newAge; } 
    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 age; 
}; 
                                                                        
Animal::Animal(int newAge): 
age(newAge) 
{ 
    std::cout << "Animal constructor ...\n"; 
} 
                                                                        
class Pet : public Animal 
{ 
public: 
    Pet(int newAge):Animal(newAge) 
           { std::cout << "Pet constructor ...\n";} 
    virtual ~Pet() { std::cout << "Pet destructor ...\n";} 
    virtual void reproduce() const 
           { std::cout << "Pet reproduction depicted ...\n"; } 
}; 
                                                                        
class Fish : public Animal 
{ 
public: 
    Fish(int newAge):Animal(newAge) 
           { std::cout << "Fish constructor ...\n";} 
    virtual ~Fish() 
          { std::cout << "Fish destructor ...\n";  } 
    virtual void sleep() const 
          { std::cout << "Fish snoring ...\n"; } 
    virtual void eat() const 
          { std::cout << "Fish feeding ...\n"; } 
    virtual void reproduce() const 
          { std::cout << "Fish laying eggs ...\n"; } 
    virtual void move() const 
          { std::cout << "Fish swimming ...\n";   } 
    virtual void speak() const { } 
}; 
                                                                        
class Horse : public Pet 
{ 
public: 
    Horse(int newAge, COLOR newColor): 
         Pet(newAge), color(newColor) 
          { std::cout << "Horse constructor ...\n"; } 
    virtual ~Horse() 
          { std::cout << "Horse destructor ...\n"; } 
    virtual void speak() const 
          { std::cout << "Whinny!\n"; } 
    virtual COLOR getcolor() const 
          { return color; } 
    virtual void sleep() const 
          { std::cout << "Horse snoring ...\n"; } 
    virtual void eat() const 
          { std::cout << "Horse feeding ...\n"; } 
    virtual void move() const 
          { std::cout << "Horse running ...\n";} 
                                                                        
protected: 
    COLOR color; 
}; 
                                                                        
class Dog : public Pet 
{ 
public: 
    Dog(int newAge, COLOR newColor ): 
         Pet(newAge), color(newColor) 
          { std::cout << "Dog constructor ...\n"; } 
    virtual ~Dog() 
          { std::cout << "Dog destructor ...\n"; } 
    virtual void speak() const 
          { std::cout << "Whoof!\n"; } 
    virtual void sleep() const 
           { std::cout << "Dog snoring ...\n"; } 
    virtual void eat() const 
           { std::cout << "Dog eating ...\n"; } 
    virtual void move() const 
           { std::cout << "Dog running...\n"; } 
    virtual void reproduce() const 
           { std::cout << "Dogs reproducing ...\n"; } 
                                                                        
protected: 
    COLOR color; 
}; 
                                                                        
int main() 
{ 
    Animal *pAnimal = 0; 
    int choice; 
    bool fQuit = false; 
                                                                        
    while (1) 
    { 
           std::cout << "(1) Dog (2) Horse (3) Fish (0) Quit: "; 
           std::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) 
               break; 
                                                                        
          pAnimal->speak(); 
          pAnimal->eat(); 
          pAnimal->reproduce(); 
          pAnimal->move(); 
          pAnimal->sleep(); 
           delete pAnimal; 
           std::cout << "\n"; 
    } 
    return 0; 
}

Result


Related Tutorials