17.8 Summary

Inheritance extends the concept of object re-use in object oriented programming by allowing new classes to be derived from existing classes, with those new classes subsequently extended to add new functionality. When an existing class provides some, but not all, of the functionality required by the programmer, inheritance allows that class to be used as the basis for a new subclass. The new subclass will inherit all the capabilities of the parent class, but may then be extended to add the missing functionality.