多态的应用 虚函数

#include<iostream>
using namespace std;
//在父类对象中 子类还未初始化 所以在构造函数中没有多态 所以在析构函数中也没有多态
class Animal{
public:
Animal(){sleep();}
virtual ~Animal(){shout();}
void play(){
eat();
shout();
sleep();
}
virtual void eat(){cout<<"吃"<<endl;}
virtual void shout(){cout<<"叫"<<endl;}
virtual void sleep(){cout<<"睡觉"<<endl;}
};


class Horse:public Animal{
public:
Horse(){cout<<"马"<<endl;}
~Horse(){cout<<"死马"<<endl;}


virtual void eat(){cout<<"马吃草"<<endl;}
virtual void shout(){cout<<"马叫唤"<<endl;}
virtual void sleep(){cout<<"马睡觉"<<endl;}
};


class Tiger:public Animal{
public:
Tiger(){cout<<"老虎"<<endl;}
~Tiger(){cout<<"死老虎"<<endl;}
virtual void eat(){cout<<"老虎吃肉"<<endl;}
virtual void shout(){cout<<"老虎吼叫"<<endl;}
virtual void sleep(){cout<<"老虎扒着睡"<<endl;}
};


int main()
{
Animal* p = NULL;
char choice;
cout<<"h---马，t---老虎，请选择：";
cin>>choice;
if('h' == choice)
{
p = new Horse;
p->play();
delete p;
}
else if('t' == choice)
{
p = new Tiger;
p->play();
delete p;
}
else
cout<<"你傻逼阿。。。 "<<endl;

return 0;



}