Book Image

Swift 4 Protocol-Oriented Programming - Third Edition

By : Jon Hoffman
Book Image

Swift 4 Protocol-Oriented Programming - Third Edition

By: Jon Hoffman

Overview of this book

Swift has become the number one language used in iOS and macOS development. The Swift standard library is developed using protocol-oriented programming techniques, generics, and first-class value semantics; therefore, every Swift developer should understand these powerful concepts and how to take advantage of them in their application design. This book will help you understand the differences between object-oriented programming and protocol-oriented programming. It will demonstrate how to work with protocol-oriented programming using real-world use cases. You will gain a solid knowledge of the various types that can be used in Swift and the differences between value and reference types. You will be taught how protocol-oriented programming techniques can be used to develop very flexible and easy-to-maintain code. By the end of the book, you will have a thorough understanding of protocol-oriented programming and how to utilize it to build powerful and practical applications.
Table of Contents (15 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Enumerations


In most languages, enumerations are little more than a data type consisting of a set of named values called elements. In Swift, however, enumerations have been supercharged to give them significantly more power. Enumerations in Swift are a lot closer in functionality to classes and structures; however, they can still be used like enumerations in other languages.

Before we see how enumerations are supercharged in Swift, let's see how we can use them as standard enumerations. The following code defines an enumeration called Devices:

enum Devices 
{  
  case IPod  
  case IPhone  
  case IPad 
} 

In the Devices enumeration, we defined three possible values: IPod, IPhone, and IPad. One of the reasons why enumerations are different in Swift as compared to other languages is that they can be prepopulated with values known as raw values. As shown in the following example, we could redefine our Devices enumeration to be prepopulated with String values:

enum Devices: String {  
  case IPod...