Abstract Class

An abstract class is a class that contains at least one pure virtual function. An abstract class is used as base class for deriving specific classes of the same kind. It defines properties common to other classes derived from it. Since an abstract class contains one or more functions for which there is no definition, no objects can be created using an abstract class. However, you can create pointers to an abstract class. This allows an abstract class to be used as a base class. A pointer to an abstract class can be used to select the proper virtual function.