C++语言基础 例程 纯虚函数

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纯虚函数应用

#include "iostream"using namespace std;class Animal{public:    virtual void cry() = 0;};class Mouse : public Animal{public:    void cry()    {        cout<<"吱！"<<endl;    }};class Cat : public Animal{public:    virtual void cry()    {        cout<<"喵！"<<endl;    }};class Dog : public Animal{public:    virtual void cry()    {        cout<<"汪！"<<endl;    }};int main( ){    Animal *p;    //p = new Animal();    //p->cry();    Mouse m1;    p=&m1;    p->cry();    Cat c1;    p=&c1;    p->cry();    Dog d1;    p=&d1;    p->cry();    return 0;}