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)

How ARC works

Whenever we create a new instance of a class, ARC allocates the memory needed to store that class. This ensures that there is enough memory to store the information associated with that instance of the class, and also locks the memory so that nothing overwrites it. When the instance of the class is no longer needed, ARC will release the memory allocated for the class so that it can be used for other purposes. This ensures that we are not tying up memory that is no longer needed.

If ARC were to release the memory for an instance of a class that is still needed, it would not be possible to retrieve the class information from memory. If we did try to access the instance of the class after the memory was released, there is a possibility that the application would crash or the data would be corrupt. To ensure memory is not released for an instance of a class that is still...