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)

Introducing subscripts

Subscripts, in the Swift language, are used as shortcuts for accessing elements of a collection, list, or sequence. We can use them in our custom types to set or retrieve the values by index rather than using getter and setter methods. Subscripts, if used correctly, can significantly enhance the usability and readability of our custom types.

We can define multiple subscripts for a single type. When types have multiple subscripts, the appropriate subscript will be chosen based on the type of index passed in with the subscript. We can also set external parameter names for our subscripts that can help distinguish between subscripts that have the same types.

We use custom subscripts just like we use subscripts for arrays and dictionaries. For example, to access an element in an array, we use the Array[index] syntax. When we define a custom subscript for our...