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 a class that works with two constrained generic types


Now, it is time to code another protocol that will be used as a constraint later, when we define another class that takes advantage of generics with two constrained generic types. The following lines show the code for the DeeJayProtocol protocol. The public modifier followed by the protocol keyword and the protocol name, DeeJayProtocol, composes the protocol declaration, as follows. The code file for the sample is included in the swift_3_oop_chapter_06_10 folder:

    public protocol DeeJayProtocol { 
      var name: String { get } 
     
      init(name: String) 
     
      func playMusicToDance() 
      func playMusicToSing() 
    } 

The protocol declares a name: String read-only stored property and two method requirements: playMusicToDance and playMusicToSing. As you

learned in the previous chapter, the protocol includes only the method declaration because the classes that conform to...