Programming iOS 14

Preface

Aut lego vel scribo; doceo scrutorve sophian.

Sedulius Scottus

Back in 2005, when Apple started to contemplate making the iPhone programmable, there was already a well-established mature application programming interface (API) for programming the Mac — Cocoa. Therefore, as the iPhone grew to fruition, the core Cocoa frameworks were adapted for it, forming Cocoa Touch. The Foundation framework, containing basic classes like NSString and NSArray, was migrated to the phone more or less unchanged; AppKit, containing interface classes like NSWindow and NSView, was simplified and rationalized to form UIKit, with classes such as UIViewController and UIView. Cocoa Touch was made available to developers in 2008, and has been the main way to program Apple’s mobile devices ever since.

The language that developers used for Cocoa Touch programming was originally Objective-C. But in July of 2010, Chris Lattner created a folder on his computer called Shiny, and a new computer language was born. Four years later, in 2014, that language, renamed Swift, was offered to developers as an alternative way of programming iOS. Since then, the Swift language has attained a high degree of maturity. Among other things, it has achieved ABI stability, which means that it has become part of the system. Swift apps are smaller and faster than ever. It is fair to assume that, for the vast majority of iOS programmers, Swift is the language of choice.

This book, then, is about programming iOS, the system ...