Book Image

Mastering Swift 5 - Fifth Edition

By : Jon Hoffman
Book Image

Mastering Swift 5 - Fifth Edition

By: Jon Hoffman

Overview of this book

Over the years, the Mastering Swift book has established itself amongst developers as a popular choice as an in-depth and practical guide to the Swift programming language. The latest edition is fully updated and revised to cover the new version: Swift 5. Inside this book, you'll find the key features of Swift 5 easily explained with complete sets of examples. From the basics of the language to popular features such as concurrency, generics, and memory management, this definitive guide will help you develop your expertise and mastery of the Swift language. Mastering Swift 5, Fifth Edition will give you an in-depth knowledge of some of the most sophisticated elements in Swift development, including protocol extensions, error handling, and closures. It will guide you on how to use and apply them in your own projects. Later, you'll see how to leverage the power of protocol-oriented programming to write flexible and easier-to-manage code. You will also see how to add the copy-on-write feature to your custom value types and how to avoid memory management issues caused by strong reference cycles.
Table of Contents (20 chapters)

Optional chaining

Optional binding allows us to unwrap one optional at a time, but what would happen if we had optional types embedded within other optional types? This would force us to have optional binding statements embedded within other optional binding statements. There is a better way to handle this: by using optional chaining. Before we look at optional chaining, let's see how this would work with optional binding. We will start off by defining three types that we will be using for our examples in this section:

class Collar { 
   var color: String  
   init(color: String) { 
         self.color = color 
   } 
} 
 
class Pet { 
   var name: String  
   var collar: Collar?  
   init(name: String) { 
         self.name = name 
   } 
} 
 
class Person { 
   var name: String  
   var pet: Pet?  
   init(name: String) { 
         self.name = name 
   } 
}

In this example...