动态多态-实现基类和派生类同名函数问题

//动态多态-实现基类和派生类同名函数问题
#include <iostream>
#include <string>
using namespace std;

class Student{
    public:
        Student(int,string,float);
        virtual void display();
    protected:
        int num;
        string name;
        float score;
};
Student::Student(int n,string nam,float s){
    num = n;name = nam;score = s;
}
void Student::display(){
    cout<<"num:"<<num<<"\nname:"<<name<<"\nscore:"<<score<<"\n\n";
}
class Graduate:public Student{
    public:
        Graduate(int,string,float,float);
        void display();
    private:
        float wage;
};
Graduate::Graduate(int n,string nam,float s,float w):Student(n,nam,s),wage(w){
}
void Graduate::display(){
    cout<<"num:"<<num<<"\nname:"<<name<<"\nscore"<<score<<"\nwage="<<wage<<endl;
}

int main(){
    Student stu1(1000,"rice",87.9);
    Graduate grad1(2001,"Rice",90.0,1200);
    Student *pt = &stu1;
    pt->display();
    pt = &grad1;
    pt->display();    //同一个pt指针，实现对象的多态性，当然，你也可以用两个不同得指针实现，但这就不是多态性了（记住多态的定义） 
    return 0;
}