[C++] Abstract class

EX :

class AbstractClass {
public:
  virtual void AbstractMemberFunction() = 0; // Pure virtual function makes
                                             // this class Abstract class.
  virtual void NonAbstractMemberFunction1(); // Virtual function.

  void NonAbstractMemberFunction2();
};

Pure virtual function : must be overridden

Abstract class cannot be initialized (cannot to create  object), but we can use a abstract class as pointer 's type to realize polymorphism.