c++ 虚拟方法

[c++]代码库

#include <iostream>
using std::cout;

class Mammal {
public:
	Mammal() :
			itsAge(1) {
		cout << "Mammal constructor...\n";
	}
	virtual ~Mammal() {
		cout << "Mammal destructor...\n";
	}
	void Move() const {
		cout << "Mammal move one step\n";
	}
	virtual void Speak() const {
		cout << "Mammal speak!\n";
	}

protected:
	int itsAge;
};

class Dog: public Mammal {
public:
	Dog() {
		cout << "Dog Constructor...\n";
	}
	virtual ~Dog() {
		cout << "Dog destructor...\n";
	}
	void WagTail() {
		cout << "Wagging Tail...\n";
	}
	void Speak() const {
		cout << "Woof!\n";
	}
	void Move() const {
		cout << "Dog moves 5 steps...\n";
	}
};

int main() {
	Mammal *pDog = new Dog;
	pDog->Move();
	pDog->Speak();

	return 0;
}