What’s New in Xcode 9
With everything you need to create amazing apps for Apple platforms, Xcode 9 is unbelievably quick and consistently smooth 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.