苹果公司在 WWDC 2014 开幕 Keynote 上发布的全新编程语言,具有更多现代化特性,同时容易使用,定位是补充 Objective-C.
> Swift is an innovative new programming language for Cocoa and Cocoa Touch. Writing code is interactive and fun, the syntax is concise yet expressive, and apps run lightning-fast. Swift is ready for your next iOS and OS X project — or for addition into your current app — because Swift code works side-by-side with Objective-C.