第14周阅读程序

/*
* 程序的版权和版本声明部分
* Copyright (c)2013, 烟台大学计算机学院学生
* All rightsreserved.
* 文件名称：score.cpp
* 作    者：   刘明亮
* 完成日期： 2013 年5 月31 日
* 版本号： v1.0
* 输入描述：
* 问题描述:
* 输出：
*/
#include <iostream>
using namespace std;
class Vehicle  //交通工具
{
public:
    void run() const
    {
        cout << "run a vehicle. "<<endl;
    }
};
class Car: public Vehicle  //汽车
{
public:
    void run() const
    {
        cout << "run a car. "<<endl;
    }
};
class Airplane: public Vehicle  //飞机
{
public:
    void run() const
    {
        cout << "run a airplane. "<<endl;
    }
};
int main()
{
    cout<<"(a) 直接用对象访问成员函数: "<<endl;
    Vehicle v;
    v.run();
    Car car;
    Airplane airplane;
    car.run();
    airplane.run();
    cout<<"(b)用指向基类的指针访问成员函数: "<<endl;
    Vehicle *vp;
    vp=&car;
    vp->run();
    vp=&airplane;
    vp->run();
    return 0;
}

#include <iostream>
using namespace std;
class Vehicle  //交通工具
{
public:
    virtual void run() 
    {
        cout << "run a vehicle. "<<endl;
    }
};
class Car: public Vehicle  //汽车
{
public:
    void run() const
    {
        cout << "run a car. "<<endl;
    }
};
class Airplane: public Vehicle  //飞机
{
public:
    void run() const
    {
        cout << "run a airplane. "<<endl;
    }
};
int main()
{
    cout<<"(a) 直接用对象访问成员函数: "<<endl;
    Vehicle v;
    v.run();
    Car car;
    Airplane airplane;
    car.run();
    airplane.run();
    cout<<"(b)用指向基类的指针访问成员函数: "<<endl;
    Vehicle *vp;
    vp=&car;
    vp->run();
    vp=&airplane;
    vp->run();
    return 0;
}



#include <iostream>
using namespace std;
class Vehicle  //交通工具
{
public:
    virtual void run() const=0;

};
class Car: public Vehicle  //汽车
{
public:
    void run() const
    {
        cout << "run a car. "<<endl;
    }
};
class Airplane: public Vehicle  //飞机
{
public:
    void run() const
    {
        cout << "run a airplane. "<<endl;
    }
};
int main()
{
    cout<<"(a) 直接用对象访问成员函数: "<<endl;
    //Vehicle v;
    //v.run();
    Car car;
    Airplane airplane;
    car.run();
    airplane.run();
    cout<<"(b)用指向基类的指针访问成员函数: "<<endl;
    Vehicle *vp;
    vp=&car;
    vp->run();
    vp=&airplane;
    vp->run();
    return 0;
}