c++ 多态性 （动物）

[c++]代码库

#include <iostream>
using namespace std;
class Animal
{
public:
	Animal ( int );
	virtual ~Animal() {cout<<"析构动物...\n";}
	virtual int GetAge() {return itsage;}
	virtual void Sleep() =0;
	virtual void Propagate() =0;
	virtual void Move() =0;
	virtual void Body() =0;
	virtual void Eat() =0;
	virtual void Show() =0;
private:
	int itsage;
};
Animal::Animal ( int age ) :itsage ( age )
{
	cout<<"创建动物...\n";
}
class Mammalia:public Animal
{
public:
	Mammalia ( int age ) :Animal ( age )
	{
		cout<<"创建哺乳类...\n";
	}
	virtual ~Mammalia()
	{
		cout<<"析构哺乳类...\n";
	}
	virtual void Propagate()
	{
		cout<<"哺乳类是胎生动物，通过胚胎来繁殖后代。\n";
	}
};
class Bird:public Animal
{
public:
	Bird ( int age ) :Animal ( age )
	{
		cout<<"创建鸟类...\n";
	}
	virtual ~Bird()
	{
		cout<<"析构鸟类...\n";
	}
	virtual void Sleep()
	{
		cout<<"鸟类喜欢站着睡觉。\n";
	}
	virtual void Eat()
	{
		cout<<"极个别鸟类吃肉，其他都是吃素。\n";
	}
	virtual void Propagate()
	{
		cout<<"鸟类是卵生动物，通过排卵来繁殖后代。\n";
	}
	virtual void Move()
	{
		cout<<"鸟类可以飞...\n";
	}
	virtual void Body()
	{
		cout<<"鸟类体表被覆羽毛，前肢变为翼！\n";
	}
	virtual void Show()
	{
		cout<<"鸟类的一般寿命为："<<GetAge() <<"年"<<endl;
	}
};
class Human:public Mammalia
{
public:
	Human ( int age ) :Mammalia ( age )
	{
		cout<<"创建人类...\n";
	}
	virtual ~Human()
	{
		cout<<"析构人类...\n";
	}
	virtual void Sleep()
	{
		cout<<"人类要在床上睡觉。\n";
	}
	virtual void Eat()
	{
		cout<<"大多数人不吃生食。\n";
	}
	virtual void Propagate()
	{
		cout<<"人类通过胚胎繁殖后代。\n";
	}
	virtual void Move()
	{
		cout<<"人类靠两条腿走路...\n";
	}
	virtual void Body()
	{
		cout<<"人类体表无毛！\n";
	}
	virtual void Show()
	{
		cout<<"人类的一般寿命为："<<GetAge() <<"年"<<endl;
	}
};
class Pig:public Mammalia
{
public:
	Pig ( int age ) :Mammalia ( age )
	{
		cout<<"创建猪类...\n";
	}
	virtual ~Pig()
	{
		cout<<"析构猪类...\n";
	}
	virtual void Sleep()
	{
		cout<<"猪喜欢在烂泥里睡觉。\n";
	}
	virtual void Eat()
	{
		cout<<"猪是杂食类动物。\n";
	}
	virtual void Propagate()
	{
		cout<<"猪也通过胚胎繁殖后代。\n";
	}
	virtual void Move()
	{
		cout<<"猪靠四条腿走路...\n";
	}
	virtual void Body()
	{
		cout<<"猪体表被毛！\n";
	}
	virtual void Show()
	{
		cout<<"猪因为要被人宰了吃，所以一般寿命为："<<GetAge() <<"年"<<endl;
	}
};
int main()
{
	Animal*p=0;
	int choice=0;
	bool quit=false;
	while ( 1 )
	{
		cout<<"(1)猪类(2)人类(3)鸟类(0)退出";
		cin>>choice;
		switch ( choice )
		{
		case 1:
			p=new Pig ( 1 );
			break;
		case 2:
			p=new Human ( 80 );
			break;
		case 3:
			p=new Bird ( 50 );
			break;
		default:
			quit=true;
			break;
		}
		if ( quit )
		{
			break;
		}
		p->Show();
		p->Eat();
		p->Propagate();
		p->Move();
		p->Sleep();
		p->Body();
		cout<<"\n";
		delete p;
	}
	return 0;
}