C++多态特性例

#include<iostream>#include<string>using namespace std;class fruit{public:virtual void how_to_eat()const=0;virtual void show_priority()const=0;        fruit(string a,string b,double c);string name;string color;double price;};class apple:public fruit{public:apple();void how_to_eat()const;void show_priority()const;};class bnana:public fruit{public:bnana();void show_priority()const;void how_to_eat()const;};fruit::fruit(string a,string b,double c):name(a),color(b),price(c){}apple::apple():fruit("apple","red",1.23){}bnana::bnana():fruit("bnana","yellow",0.34){}void apple::how_to_eat()const{cout<<"直接吃"<<endl;}void apple::show_priority()const{cout<<name<<endl<<color<<endl<<price<<endl;}void bnana::how_to_eat()const{cout<<"去了皮再吃"<<endl;}void bnana::show_priority()const{cout<<name<<endl<<color<<endl<<price<<endl;}int main(){fruit *p[2]={NULL};p[0]=new apple;p[1]=new bnana;for(int i=0;i<2;i++){p[i]->show_priority();p[i]->how_to_eat();}return 0;}