Mastering Swift 3

Object-Oriented design

Before we start writing code, let's create a very basic class diagram that shows how we would design the Animal class hierarchy. I usually start off by making a very basic diagram that simply shows the classes themselves without much detail. This helps me picture the class hierarchy in my mind. The following diagram shows the class hierarchy for the Object-Oriented design:

This diagram shows that we have one superclass named Animal and two subclasses named Alligator and Lion. We may think that with the three categories (land, air, and sea) that we would want to create, a larger class hierarchy where the middle layer would ...