So far, we have only dealt with freestanding classes, let us now put three classes together in a class hierarchy. We start with the baseclass Person, which has a constructor that initializes the field m_stName, and a method Print that writes the name. Print is marked as virtual; this means that dynamic binding will come into effect when we, in the main function, define a pointer to an object of this class. We do not have to mark the methods as virtual in the subclasses, it is sufficient to do so in the baseclass. The constructors of a class cannot be virtual. However, every other member, including the destructor, can be virtual and I advise you to always mark them as virtual in your baseclass. Non-virtual methods are not a part of the object-oriented model and were added to C++ for performance reasons only.

class Person
{
  public:
    Person(string stName);
    virtual void Print() const;
  private:
    string m_stName;
};

#include <iostream>
#include ...