Book Image

Swift 3 Object-Oriented Programming - Second Edition

By : Gaston C. Hillar
Book Image

Swift 3 Object-Oriented Programming - Second Edition

By: Gaston C. Hillar

Overview of this book

Swift has quickly become one of the most-liked languages and developers’ de-facto choice when building applications that target iOS and macOS. In the new version, the Swift team wants to take its adoption to the next level by making it available for new platforms and audiences. This book introduces the object-oriented paradigm and its implementation in the Swift 3 programming language to help you understand how real-world objects can become part of fundamental reusable elements in the code. This book is developed with XCode 8.x and covers all the enhancements included in Swift 3.0. In addition, we teach you to run most of the examples with the Swift REPL available on macOS and Linux, and with a Web-based Swift sandbox developed by IBM capable of running on any web browser, including Windows and mobile devices. You will organize data in blueprints that generate instances. You’ll work with examples so you understand how to encapsulate and hide data by working with properties and access control. Then, you’ll get to grips with complex scenarios where you use instances that belong to more than one blueprint. You’ll discover the power of contract programming and parametric polymorphism. You’ll combine generic code with inheritance and multiple inheritance. Later, you’ll see how to combine functional programming with object-oriented programming and find out how to refactor your existing code for easy maintenance.
Table of Contents (17 chapters)
Swift 3 ObjectOriented Programming - Second Edition
Credits
About the Author
Acknowledgement
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Generalizing existing classes with generics


In Chapter 3, Encapsulation of Data with Properties, we created a class to represent a mutable 3D vector named MutableVector3D and a class to represent an immutable version of a 3D vector named ImmutableVector3D.

Both the versions were capable of working with 3D vectors with Float values for x, y, and z. We now realize that we also have to work with 3D vectors with Double values for x, y, and z in both classes. We definitely don't want to create two new classes, such as MutableDoubleVector3D and ImmutableDoubleVector3D. We can take advantage of generics to create two classes capable of working with elements of any floating point type supported in Swift--that is, either Float, Float80, or Double.

We want to create the following two classes:

  • MutableVector3D<T>

  • ImmutableVector3D<T>

It is a pretty simple task. We just have to replace Float with the generic type parameter, T, and change the class declaration to include the necessary generic...