This book teaches you how to master the Swift programming language and use it in building apps with the new technologies introduced in iOS 8. Swift is a new programming language for iOS, OS X, and watchOS apps. In the beginning of this book, we will give you an advanced introduction to Swift, and then we will see how to apply this in real-app demos using the new technologies and APIs in iOS 8 such as TouchID, watchOS, Metal, and HealthKit.
Chapter 1, Hello Swift, gives a quick introduction and revision about Swift. This chapter is very important for Swift beginners and is highly recommended for Swift developers to revise their knowledge.
Chapter 2, Advanced Swift, boosts your Swift experience by allowing you to learn some advanced features in Swift. In this chapter, we will talk about protocols, extensions, and memory management.
Chapter 3, Touch ID, gives your app a new flavor of authentication using Touch ID. Users can now use their fingerprint to sign in to your app without needing to write their username and password.
Chapter 4, Introduction to HealthKit, teaches you how to work with HealthKit and how to share or read health data in the native Health app. If you have any apps or ideas about health or fitness, you should give this chapter a shot.
Chapter 5, Introduction to Metal, introduces a cutting edge technology for 3D GPU-accelerated graphics in iOS.
Chapter 6, Introduction to WatchKit, introduces a new device for you—the Apple watch. You will learn all the new technologies needed to build apps for the Apple watch and get your app prepared to exist on users wrists.
Chapter 7, Swift App Extensions, teaches you how to let your users use the app even if your app is not open, using app extensions. App extensions let you extend your app's functionality outside your app and users can access it using system or third-party apps.
To work on this book, some programming experience is expected. Having experience with Objective-C and iOS development will help you a lot while working with this book. You will also need a Mac OS with Xcode 6+ installed.
If you are an iOS developer with experience in Objective-C, and wish to develop applications with Swift, then this book is ideal for you. Familiarity with the fundamentals of Swift is an added advantage but not a necessity.
In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.
Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "In Swift, you use var for variables, and let for constants."
A block of code is set as follows:
var count = 5 var msg : String var total : Double = 0
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
Protocol <protocol1, protocol2,…>
New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Xcode helps you with this by providing the history button in the results sidebar, on the line of the number of times."
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