C++问题,谢谢大虾.

定义一个车(vehicle)基类，有Run、Stop等成员函数，由此派生出自行车(bicycle)类、汽车(motorcar)类，从bicycle和motorcar派生出摩托车(motorcycle)类，它们都有Run、Stop等成员函数。观察虚函数的作用。

class vehicle

{

public:

void Run(){cout<<"Run in vehicle\n";}

virtual void Stop(){cout<<"Stop in vehicle\n";}

};

class bicycle : public vehicle

{

public:

void Run(){cout<<"Run in bicycle\n";}

virtual void Stop(){cout<<"Stop in bicycle\n";}

};

class motorcar : public vehicle

{

public:

virtual void Stop(){cout<<"Stop in motorcar\n";}

};

class motorcycle : pulic vehicle, public motocar

{

public:

virtual void Stop(){count<<"Stop in motorcycle\n";}

};

void main()

{

vehicle v, *v;

bicycle b;

motorcar m;

motorcycle mb;

v.Run();

b.Run();

//m.Run();

//mb.Run();

v.Stop();

b.Stop();

m.Stop();

mb.Stop();//不论虚函数与否,类对象总是访问自己的函数

//而我们希望的是用基类的指针访问子类的函数,那样我们只需要一个指

//针就可以访问当前不同子类的同一个函数了.这在实际当中很有用.

v = &b;

v->Stop();

v = &m;

v->Stop();

v = &mb;

v->Stop();

}

水平有限,给你讲不太清楚,可以好好看看书,书上讲的好.