Moodle 3.x Developer's Guide

An object-oriented philosophy

Object orientation is all about treating features of a system as little interconnecting black boxes. We have no idea what goes on inside a black box, but each black box can be described in three ways:

• Each box behaves in a particular way and by making a box act out predefined, built-in behaviors, you can make it do different things
• At any moment, a box is in a particular state
• Every box has its own identity

Also, in fact, our little black boxes are objects and each object has a state, exhibits certain behaviors, and every object is uniquely identifiable as each has its own identity.

Objects themselves are of a particular type, called a class. Your pet cat shares some of the features of a mountain lion because ...