The Book of Ruby

Classes and Objects

Instead of going through all the rest of Ruby’s syntax—its types, loops, modules, and so on—let’s move rapidly on and look at how to create classes and objects. (But fear not, we’ll return to those other topics soon.)

Basic Terminology: Classes, Objects, and Methods

A class is the blueprint for an object. It defines the data an object contains and the way it behaves. Many different objects can be created from a single class. So, you might have one Cat class but three cat objects: tiddles, cuddles, and flossy. A method is like a function or subroutine that is defined inside the class.

It may seem like no big deal to say that Ruby is object-oriented. Aren’t all languages these days? Well, up to a point. Most modern “object-oriented” ...