protected:

string name;

public:

Animal(string s="Noname") : name(s) { } // Default value = "Noname"

// Pure virtual method - must be overridden by non-abstract derived class

virtual void speak() = 0;

// Virtual method - can be overridden by the child class. The type of the

// *OBJECT* being pointed to determines the method that gets called.

virtual void move() { cout << " ANIMAL " << name << " : I'm moving" << endl; }

// Non-virtual method - can be overridden by the child class. The type

// of the *POINTER* being used determines the method that gets called.

void eat() { cout << " ANIMAL " << name << " : I'm hungry!" << endl; }

public:

Dog(string s="GoodBoy") : Animal(s) {}

void speak() override { cout << " DOG " << name << " : Woof!" << endl; }

void move() override { cout << " DOG " << name << " : I'm running!" << endl; }

void fetch() { cout << " DOG " << name << " : Ball! Ball!" << endl; }

public:

Cat(string s="Kitty") : Animal(s) {}

void speak() override { cout << " CAT " << name << " : Meow!" << endl; }

virtual void move() override { cout << " CAT " << name << " : Later." << endl; }

/* // Can't instantiate an Animal object

Animal * adPtr;

Dog d("Spot");

Dog * dPtr;

Dog & dRef = d;

Cat c("Eek");

Cat * cPtr;

Cat & cRef = c;

Animal & acRef = c;

/* // Can't instantiate an Animal object

cout << endl << "Dog object: " << endl;

d.speak();

d.move();

d.eat();

d.fetch();

cout << endl << "Dog pointer to an Dog object: " << endl;

dPtr = new Dog("Felix");

dPtr->speak();

dPtr->move();

dPtr->eat();

dPtr->fetch();

cout << endl << "Animal pointer to an Dog object: " << endl;

adPtr = &d;

adPtr->speak();

adPtr->move();

adPtr->eat();

// adPtr->fetch(); // Animal class has no 'fetch' member

cout << endl << "Dog reference to an dog object: " << endl;

dRef.speak();

dRef.move();

dRef.eat();

dRef.fetch();

cout << endl << "Cat object: " << endl;

c.speak();

c.move();

c.eat();

cout << endl << "Cat pointer to an Cat object: " << endl;

cPtr = new Cat("Mittens");

cPtr->speak();

cPtr->move();

cPtr->eat();

cout << endl << "Cat reference to an cat object: " << endl;

cRef.speak();

cRef.move();

cRef.eat();

cout << endl << "Animal reference to an cat object: " << endl;

acRef.speak();

acRef.move();

acRef.eat();

return 0;