Dive into Swift 4.x, the latest version of Apple's easy-to-use programming language for macOS, iOS, watchOS, and tvOS. With this practical guide, you'll quickly get up to speed on language basics and then use Swift to build three complete apps, all tightly linked together: an iOS note-taking app, its OSX counterpart that uses iCloud to sync data, and an app for the Apple Watch that makes the user’s data available at a moment's notice.