With everything you need to create amazing apps for Apple platforms, Xcode 9 provides a quick and smooth experience while editing even the largest files. It also understands your code better than ever, so you can select and edit the structure or even transform the selection directly in the editor. Powerful new refactoring tasks happen in place, renaming symbols across Swift, Objective-C, and even user interface files without skipping a beat. And with source compatibility in Swift 4, Xcode 9 uses the same compiler to build existing Swift 3 code and updated Swift 4 code, so you can migrate at your own pace.
The source code editor has been completely rebuilt for amazing speed. It scrolls at a constantly smooth rate, no matter the files size. And it looks better, too, with preferences that give you greater control over line spacing, multiple font styles, and even the type of cursor. The new command-click gesture makes it easy to visualize and select sections of code based on structure. Issues have been redesigned to flow nicely with your code with Fix-its are grouped together so you can commit multiple changes in a single click.
Because everything is so well integrated, workflows feel natural. As you compose a new interface, the Assistant editor intuitively presents the related source code in a split window pane. Simply drag the mouse to connect UI controls to the implementation code. Apple LLVM compiler technologies parse your code, keeping every symbol you see in the LLDB debugger consistent with the editor and compiler. As you type, that same engine is constantly at work, finding mistakes and offering Fix-its for your code. Xcode even communicates with the Apple developer website, so you can enable services such as Game Center or Passbook in your app with a single click. When your app is ready, Xcode will bundle and submit your app to the App Store.
Xcode 9 makes working with source control – and with GitHub – easier and more tightly integrated. With your GitHub account built into Xcode, the clone window shows all of your personal GitHub repositories, as well as all the repositories where you added a star. From this window, you can search all of GitHub and check out a project with just a click.