虚函数

#include <iostream>

using namespace std;

//基类People

class People{

public:

    People(char *name, int age);

    virtual void display();  //声明为虚函数

protected:

    char *m_name;

    int m_age;

};

People::People(char *name, int age): m_name(name), m_age(age){}

void People::display(){

    cout<<m_name<<"今年"<<m_age<<"岁了，是个无业游民。"<<endl;

}

//派生类Teacher

class Teacher: public People{

public:

    Teacher(char *name, int age, int salary);

    virtual void display();  //声明为虚函数

private:

    int m_salary;

};

Teacher::Teacher(char *name, int age, int salary): People(name, age), m_salary(salary){}

void Teacher::display(){

    cout<<m_name<<"今年"<<m_age<<"岁了，是一名教师，每月有"<<m_salary<<"元的收入。"<<endl;

}

int main(){

    People *p = new People("王志刚", 23);

    p -> display();

    p = new Teacher("赵宏佳", 45, 8200);

    p -> display();

    return 0;

}