C++ Polymorphism

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Polymorphism

Polymorphism means "many forms", and it occurs when we have many classes that are related to each other by inheritance.

Like we specified in the previous chapter; Inheritance lets us inherit attributes and methods from another class. Polymorphism uses those methods to perform different tasks. This allows us to perform a single action in different ways.

For example, think of a base class called Animal that has a method called animalSound(). Derived classes of Animals could be Pigs, Cats, Dogs, Birds - And they also have their own implementation of an animal sound (the pig oinks, and the cat meows, etc.):

Example

// Base class
class Animal {
  public:
    void animalSound() {
    cout << "The animal makes a sound \n" ;
}
};

// Derived class
class Pig : public Animal {
  public:
    void animalSound() {
    cout << "The pig says: wee wee \n" ;
  }
};

// Derived class
class Dog : public Animal {
  public:
    void animalSound() {
    cout << "The dog says: bow wow \n" ;
}
};

Now we can create Pig and Dog objects and override the animalSound() method:

Example

// Base class
class Animal {
  public:
    void animalSound() {
    cout << "The animal makes a sound \n" ;
}
};

// Derived class
class Pig : public Animal {
  public:
    void animalSound() {
    cout << "The pig says: wee wee \n" ;
   }
};

// Derived class
class Dog : public Animal {
  public:
    void animalSound() {
    cout << "The dog says: bow wow \n" ;
}
};

int main() {
Animal myAnimal;
Pig myPig;
Dog myDog;

  myAnimal.animalSound();
myPig.animalSound();
  myDog.animalSound();
  return 0;
}

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Why And When To Use "Inheritance" and "Polymorphism"?

- It is useful for code reusability: reuse attributes and methods of an existing class when you create a new class.

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C++ Polymorphism

Polymorphism

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Example

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Why And When To Use "Inheritance" and "Polymorphism"?

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C++ Polymorphism

Polymorphism

Example

Example

Try it now Why And When To Use "Inheritance" and "Polymorphism"?

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Why And When To Use "Inheritance" and "Polymorphism"?