This chapter contains conceptually complex material that is central to the course, so it is worth spending time going through it carefully. Do these exercises as you finish reading each section and if things don’t make sense, ask questions, post to the discussion forum, send emails.

As with previous chapters, the Processing-specific material is collected in the example sections; the main sections are general, Java-based in nature.

9.2. Class Design

Focus here on Sections 9.2.1-9.2.2.

9.3. Class Implementation

Focus here on Sections 9.3.1-9.3.2.

9.4. Object Interaction

This section discusses the interaction of multiple class objects. For example, consider the case of adding two coordinate objects together where we would view the result at the sum of the vectors represented by the coordinates. For example, adding the coordinates (1, 2) and (3, 4) would result in a new coordinate (4, 6).

9.5. Revisiting the Example

This chapter focuses on the Processing-based example. Go through it only if you’re interested in classes in Processing.

9.6. Object-Oriented Programming

Just read this short section and look forward to Chapter 11!