虚函数实现多态性 代码参考

#include <iostream>

using namespace std;

class Pet
{
    public:
        virtual void Speak(){cout<<"How does a pet speak?"<<endl;}
};

class Cat:public Pet
{
    public:
        void Speak(){cout<<"miao!miao!"<<endl;}
};

class Dog:public Pet
{
    public:
        void Speak(){cout<<"wang!wang!"<<endl;}
};

int main()
{
    Pet one, *p1,*p2,*p3;
    Cat two;
    Dog three;
    p1=&one;
    p2=&two;
    p3=&three;
    p1->Speak();
    p2->Speak();
    p3->Speak();
    return 0;
}