6.13-派生对象.cpp

Visual C++的课件

//Listing 11.2 Using a derived object

#include <iostream.h>
enum BREED { GOLDEN, CAIRN, DANDIE, SHETLAND, DOBERMAN, LAB };

class Mammal
{
public:
	// constructors
	Mammal():itsAge(2), itsWeight(5){}
	~Mammal(){}

	//accessors
	int GetAge() const	{ return itsAge; }
	void SetAge(int age) { itsAge = age; }
	int GetWeight() const { return itsWeight; }
	void SetWeight(int weight) { itsWeight = weight; }

	//Other methods
	void Speak()const { cout << "Mammal sound!\n"; }
	void Sleep()const { cout << "shhh. I'm sleeping.\n"; }


protected:
	int itsAge;
	int itsWeight;
};

class Dog : public Mammal
{
public:

	// Constructors
	Dog():itsBreed(GOLDEN){}
	~Dog(){}

	// Accessors
	BREED GetBreed() const { return itsBreed; }
	void SetBreed(BREED breed) { itsBreed = breed; }

	// Other methods
	void WagTail() const { cout << "Tail wagging...\n"; }
	void BegForFood() const { cout << "Begging for food...\n"; }

private:
	BREED itsBreed;
};

int main()
{
	Dog fido;
	fido.Speak();
	fido.WagTail();
	cout << "Fido is " << fido.GetAge() << " years old\n";
	return 0;
}