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)

Implementing the equatable protocol

In this section, we will demonstrate how we can conform to the Equatable protocol using extensions. When a type conforms to the Equatable protocol, we can use the equal-to (==) operator to compare for equality and the not-equal-to (!=) operator to compare for inequality.

If you will be comparing instances of a custom type, then it is a good idea to have that type conform to the Equatable protocol because it makes comparing instances very easy.

Let's start off by creating the type that we will compare. We will name this type, Place:

struct Place { 
    let id: String 
    let latitude: Double 
    let longitude: Double 
} 

In the Place type, we have three properties that represent the ID of the place and the latitude and longitude coordinates for its location. If there are two instances of the Place type that have the same ID and coordinates...