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

Strongly typed string enumerations


The Foundation framework has a lot of string-based constants. For example, UIKit uses NSNotifications to publishing notifications for an iOS app's lifecycle.

NSString *const UIApplicationDidEnterBackgroundNotification        
NSString *const UIApplicationWillEnterForegroundNotification      NSString *const UIApplicationDidFinishLaunchingNotification; 

New for Foundation, Objective-C now has the ability to use strongly typed string enumerations. This new feature allowed the Foundation team to update the enumerations in Objective-C. Our notifications listed earlier can now use the NSNotificationName type and convert our preceding constants to:

In Objective-C:

typedef NSString *NSNotificationName NS_EXTENSIBLE_STRING_ENUM; 
NSNotificationName const UIApplicationDidEnterBackgroundNotification        
NSNotificationName const UIApplicationWillEnterForegroundNotification      NSNotificationName const UIApplicationDidFinishLaunchingNotification...