1. Code reuse through subtyping
Inheritance Basics
Code reuse through subtyping

2. Inheritance : What is It
Technical mechanism for code reuse
Conceptual design mechanism : is-a relationship

3. Inheritance Terminology
Inheritance : derive a class from another class
Terminology
Parent or Base class
Derived or Child class
UML
Arrow from derived to parent class

4. Conceptual Model How to visualize inheritance:
Apple consists of a Fruit object and an Apple wrapper
Wrapper can add new features / hide existing ones
Fruit
Apple
Other Code

5. Inheritance Heirarchies
Multiple classes can derive from one base
Can derive from a class that is derived

6. Geometric Object Example
Function also available in Circle & Rectagle
Circle & Rectangle could use toString() but chose to override

7. Circle Interactions
Calls on a derived class handled by code there if possible, otherwise by parent class
Geometric Object
Circle

8. Circle Code State inheritance with : public ParentClass
Do not redeclare parent members unless overriding them

9. Using Inherited Members
Derived class does NOT have access to private members of parent:

10. Using Inherited Members
Derived class does NOT have access to private members of parent
Must use public interface to access

11. Generic Programming
A derived class can be treated as parent type:

12. Protected Access
Private Only accessible in this class

13. Protected Access Private Only accessible in this class
Public Accessible anywhere

14. Protected Access Private Only accessible in this class
Public Accessible anywhere
Protected Accessible in this class and any subclasses

15. Access Summary Private Protected Public Member variables
Helper functions no one else should use
Protected
Member variables it is reasonable for child classes to work with
Functions you only want subclasses to use
Public
Functions
Constants