Homework Review!

• Go over it, and see how it illustrates the need for multiple inheritance ... and how the limited form of multiple inheritance we get from interfaces is "good enough".

Project Review!

• Don't use tyr-catch where you really mean if-else.
• Do use try catch to detect problems (and throw exceptions) where they really cause problems, e.g. detect character problems in Caesar not in main.
• Don't forget to make functions for all the good reasons that we did in IC210 - avoid duplicate code, break out non-trivial steps into functions, where you can test, debug and puzzle through a solution in isolation from the rest of the big program.
• Don't duplicate code. When you see duplicate code, it generally means poor design.

Review!

• The purpose of iterators.
• Polymorphism: with reference Foo x, how do you figure out what methods you can call?
• Inheritance: if class Bar extends Foo, and you have references Foo x andBar y, why is it that "x = y" is OK, but "y = x" is not? Even if x actually does refer to an object of type Bar?
• OOP design reprise: class hierarchies + polymorphism rather than fields indicating type and if-else's at the calling site.
• Exceptions: how do we use inheritance and polymorphism to send information about an error from the place where it was detected to the place where it can be dealt with.
• Does Java support multiple inheritance?
• Understand the purpose of generics and how it differs from simply using a common base type (like object).