C++中的多态和虚函数

    #include 
    using namespace std;
    //基类People
    class People{
    public:
        People(char *name, int age);
        void display();
    protected:
        char *m_name;
        int m_age;
    };
    People::People(char *name, int age): m_name(name), m_age(age){}
    void People::display(){
        cout<