Inheritance and Class Hierarchies

• Figure 3.1: Throwable Class Hierarchy (notice the UML for is-a)
• Is-a Versus Has-a
• this
• super
• private, protected, public

Important Ideas

• Method Overriding
• Method Overloading
• Polymorphism

Classes vs. Abstract Classes vs. Interfaces

• Figure 3.4: Number Abstract Class
• Table 3.1