Understanding classes and instances

In the previous chapter, you learned some of the basics of the object-oriented paradigm, including classes and objects, also known as instances. Now, when you dive deep into the programming languages, the class is always going to be the type and the blueprint. The object is the working instance of the class, and one or more variables can hold a reference to an instance.

Let's move to the world of our best friends, the dogs. If we want to model an object-oriented application that has to work with dogs and about a dozen dog breeds, we will definitely have a Dog abstract class. Each dog breed required in our application will be a subclass of the Dog superclass. For example, let's assume that we have the following subclasses of Dog:

• TibetanSpaniel: This is a blueprint for the dogs that belong to the Tibetan Spaniel breed
• SmoothFoxTerrier: This is a blueprint for the dogs that belong to the Smooth Fox Terrier breed

So, each dog breed will become a subclass...