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)

Functions

When I first learned to program with the Basic programming language, my first few programs were written in one long block of code. I quickly realized that I was repeating the same code over and over, and thought that there must be a better way to do this, which was when I learned about subroutines and functions. Functions are one of the key concepts that you need to understand in order to write good code.

In this chapter, we will cover the following topics:

  • What are functions?
  • How to return values from a function
  • How to use parameters in a function
  • What are Variadic parameters?
  • What are inout parameters?

In Swift, a function is a self-contained block of code that performs a specific task. Functions are generally used to logically break our code into reusable named blocks. The function's name is used to call the function.

When we define a function, we can also...