11. An Introduction to Swift Subclassing and Extensions
In “The Basics of Swift Object-Oriented Programming” we covered the basic concepts of object-oriented programming and worked through an example of creating and working with a new class using Swift. In that example, our new class was not derived from any base class and, as such, did not inherit any traits from a parent or super class. In this chapter we will introduce the concepts of subclassing, inheritance and extensions in Swift.