READING
CHAPTER 13
SECTION 6
"Inheritance versus Interface"

- inheritance and interface
  - features to support OO modeling
  - model is-a relationships
  - intended uses very different
- interface
  - share common behavior (method headers) among instances of different classes
  - one class can implement multiple interfaces
- inheritance
  - share common code among the instances of related classes
  - a single subclass can extend at most one superclass
  - superclasses include data members and/or methods that are shared by the 
    subclasses
  - unlike interface, is a specialization relationship
- don't use inheritance to model a service class
  - *code reuse by composition* model a service class as a component (vs 
    modeling via specialization)
  - weaknesses if substitute inheritance for composition
    - clients have access to inapplicable methods
    - difficult to change implementation, because all inherited methods could 
      be used to clients