Book Image

Learning Swift Second Edition - Second Edition

By : Andrew J Wagner
Book Image

Learning Swift Second Edition - Second Edition

By: Andrew J Wagner

Overview of this book

Swift is Apple’s new programming language and the future of iOS and OS X app development. It is a high-performance language that feels like a modern scripting language. On the surface, Swift is easy to jump into, but it has complex underpinnings that are critical to becoming proficient at turning an idea into reality. This book is an approachable, step-by-step introduction into programming with Swift for everyone. It begins by giving you an overview of the key features through practical examples and progresses to more advanced topics that help differentiate the proficient developers from the mediocre ones. It covers important concepts such as Variables, Optionals, Closures, Generics, and Memory Management. Mixed in with those concepts, it also helps you learn the art of programming such as maintainability, useful design patterns, and resources to further your knowledge. This all culminates in writing a basic iOS app that will get you well on your way to turning your own app ideas into reality.
Table of Contents (19 chapters)
Learning Swift Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Using associated values effectively


Good programming is about more than just grand, universal concepts of how to write effective code. The best programmers know how to play to the strengths of the tools at hand. We are now going to move from looking at the core tenants of programming design to some of the gritty details of enhancing your code with the power of Swift.

The first thing we will look at is making effective use of the associated value of an enumeration. Associated values are a pretty unique feature of Swift, so they open up some pretty interesting possibilities.

Replacing class hierarchies

We have already seen in Chapter 3, One Piece at a Time – Types, Scopes, and Projects that we can use an enumeration with associated values to represent a measurement like distance in multiple measurement systems:

enum Height {
    case Imperial(feet: Int, Inches: Double)
    case Metric(meters: Double)
    case Other(String)
}

We can generalize this use case as using an enumeration to flatten out...