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

Changing functionality


Closures also give us the ability to change the functionality of classes on the fly. We saw in Chapter 11, Working with Generics, that generics give us the ability to write functions that are valid for multiple types. With closures, we are able to write functions and classes whose functionality can change, based on the closure that is passed into it as a parameter. In this section, we will show how to write a function whose functionality can be changed with a closure.

Let's begin by defining a class that will be used to demonstrate how to swap out functionality. We will name this class TestClass:

class TestClass { 
  typealias getNumClosure = ((Int, Int) -> Int) 
   
  var numOne = 5 
  var numTwo = 8 
   
  var results = 0 
  func getNum(handler: getNumClosure) -> Int { 
    results = handler(numOne,numTwo) 
    return results 
 
  } 
} 

We begin this class by defining a type alias for our closure...