virt_one.cpp

不错书对C++/C程序员很有用的大家不要错过.

#include <iostream.h>

class Base 
{
 public:
   virtual void show_message(void) { cout << "This is the base class\n"; };
};

class Derived: public Base 
{
 public:
   virtual void show_message(void) { cout << "This is the derived class\n" ; };
};

void main(void)
 {
   Base *base_pointer = new Base;
   base_pointer->show_message();
   
   base_pointer = new Derived;
   base_pointer->show_message();
 }