Book Image

Mastering Swift 5.3 - Sixth Edition

By : Jon Hoffman
Book Image

Mastering Swift 5.3 - Sixth Edition

By: Jon Hoffman

Overview of this book

Over the years, Mastering Swift has proven itself among developers as a popular choice for an in-depth and practical guide to the Swift programming language. This sixth edition comes with the latest features, an overall revision to align with Swift 5.3, and two new chapters on building swift from source and advanced operators. From the basics of the language to popular features such as concurrency, generics, and memory management, this in-depth guide will help you develop your expertise and mastery of the language. As you progress, you will gain practical insights into some of the most sophisticated elements in Swift development, including protocol extensions, error handling, and closures. The book will also show you how to use and apply them in your own projects. In later chapters, you will understand how to use the power of protocol-oriented programming to write flexible and easier-to-manage code in Swift. Finally, you will learn how to add the copy-on-write feature to your custom value types, along with understanding how to avoid memory management issues caused by strong reference cycles. By the end of this Swift book, you will have mastered the Swift 5.3 language and developed the skills you need to effectively use its features to build robust applications.
Table of Contents (23 chapters)
21
Other Books You May Enjoy
22
Index

When not to use a custom subscript

As we have seen in this chapter, creating custom subscripts can really enhance our code. However, we should avoid overusing them or using them in a way that is not consistent with standard subscript usage. The way to avoid overusing subscripts is to examine how subscripts are used in Swift's standard libraries.

Let's look at the following example:

class MyNames {
    private var names:[String] = ["Jon", "Kailey", "Kara"] 
    var number: Int {
        get {
            return names.count
        }
    }
    subscript(add name: String) -> String { 
        names.append(name)
            return name
    }
    subscript(index: Int) -> String { 
        get { 
            return names[index]
        }
        set {
            names[index] = newValue
        }
    }
}

In the preceding example, within the MyNames class, we define an array of names that are used within our application. As an example...