源程序：
//
// main.cpp
// virtualfunction
//
// Created by duanqibo on 2020/1/9.
// Copyright © 2020年 duanqibo. All rights reserved.
//
#include <iostream>
using namespace std;
class A
{
public:
virtual void Print()
{
cout<<"A::Print"<<endl;
}
};
class B:public A
{
public:
virtual void Print()
{
cout<<"B::Print"<<endl;
}
};
class D:public A
{
public:
virtual void Print(){
cout<<"D::Print"<<endl;
}
};
class E:public B
{
public:
virtual void Print()
{
cout<<"E::print"<<endl;
}
};
int main()
{
A a;B b;D d;E e;
A *pa = &a;
B *pb = &b;
pa->Print();
pa = pb;
pa->Print();
pa = &d;
pa->Print();
pa = &e;
pa->Print();
return 0;
}
运行结果：
