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

Declaring protocols


Now, it is time to code the protocols in Swift. We will code the following five protocols:

  • ComicCharacter

  • GameCharacter

  • Alien

  • Wizard

  • Knight

The following UML diagram shows the five protocols that we will code in Swift, with their required properties and methods included in the diagram. In this case, the diagram shows only protocols and we don't use any mark above the protocol name. However, in other diagrams in which we will mix protocols with classes, we will add procotol after the protocol name. UML diagrams have specifications for interfaces, but we will use our own mechanism to identify protocols:

The following lines show the code for the ComicCharacter protocol. The public modifier followed by the protocol keyword and the protocol name, ComicCharacter, makes up the protocol declaration. As happens with class declarations, the protocol body is enclosed in curly brackets ({}). The code file for the sample is included in the swift_3_oop_chapter_05_01 folder:

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