Book Image

Mastering Swift 3 - Linux

By : Jon Hoffman
Book Image

Mastering Swift 3 - Linux

By: Jon Hoffman

Overview of this book

Swift is a modern, fast, and safe programming language created by Apple. Writing Swift is interactive and fun, the syntax is concise yet expressive, and the code runs lightning-fast. Swift’s move to open source has been embraced with open arms and has seen increased adoption in the Linux platform. Our book will introduce you to the Swift language, further delving into all the key concepts you need to create applications for desktop, server, and embedded Linux platforms. We will teach you the best practices to design an application with Swift 3 via design patterns and Protocol-Oriented Programming. Further on, you will learn how to catch and respond to errors within your application. When you have gained a strong knowledge of using Swift in Linux, we’ll show you how to build IoT and robotic projects using Swift on single board computers. By the end of the book, you will have a solid understanding of the Swift Language with Linux and will be able to create your own applications with ease.
Table of Contents (24 chapters)
Mastering Swift 3 - Linux
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
2
Learning About Variables, Constants, Strings, and Operators

Read and write custom subscripts


Let's see how to define a subscript that is used to read and write to a backend array. Reading and writing to a backend storage class is one of the most common uses for custom subscripts but, as we will see in this chapter, we do not need to have a backend storage class. The following code shows how to use a subscript to read and write to an array:

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

As we can see, the syntax is similar to how we can define properties within a class using the get and set keywords. The difference is that we declare the subscript using the subscript keyword. We then specify one or more inputs and the return type.

We can now use the custom subscript, just like we used subscripts...