Book Image

Swift 3 New Features

By : Keith Elliott
Book Image

Swift 3 New Features

By: Keith Elliott

Overview of this book

Since Swift was introduced by Apple in WWDC 2015, it has gone on to become one of the most beloved languages to develop iOS applications with. In the new version, the Swift team aimed to take its adoption to the next level by making it available for new platforms and audiences. This book will very quickly get you up to speed and productive with Swift 3. You will begin by understanding the process of submitting new feature requests for future versions of Swift. Swift 3 allows you to develop and run your applications on a Linux machine. Using this feature, you will write your first Linux application using the debugger in Linux. Using Swift migrator, you will initiate a conversion from Swift 2.2 to Swift 3. Further on, you will learn how to interact with Cocoa libraries when importing Objective C to Swift. You will explore the function and operator changes new to Swift 3, followed by Collection and Closure changes. You will also see the changes in Swift 3 that allow you write tests easier with XCTest and debug your running code better with new formats as well. Finally, you will have a running server written completely in Swift on a Linux box. By the end of the book, you will know everything you need to know to dive into Swift 3 and build successful projects.
Table of Contents (16 chapters)
Swift 3 New Features
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
5
Function and Operator Changes – New Ways to Get Things Done

Using the REPL


Once we have Swift installed, we can use the Swift REPL (Read Evaluate Print Loop) environment and give Swift a test run on Linux. The Swift REPL environment and LLDB debugger are tightly linked to the toolchain, which aids in Swift type inference, syntax, and expression evaluation. Basically, it makes the compiler, debugger, and REPL environment's jobs easier if there is only one version of Swift to worry about at a time. Let's start the REPL environment and execute a few commands to get familiar with the REPL environment's capabilities.

To start the Swift REPL, you type the swift command:

$ swift

As we add statements, the REPL environment is smart enough to only execute once you have completely entered a statement. We can create assignment statements, functions, or even entire classes.

At the REPL prompt, let's assign:

1> let oneMillion = 1_000_000 
oneMillion: Int = 1000000 
2> let twoMillion: Int = 2_000_000 
twoMillion: Int = 2000000 
3> oneMillion...