What’s new in Swift 4

An Xcode playground showcasing the new features in Swift 4.0. As seen in the What’s New in Swift session at WWDC 2017.

Written by Ole Begemann, May–September 2017.

See also: my What’s new in Swift 4.2 playground from 2018.

The playground requires Swift 4. Xcode 9 includes Swift 4 by default.

You can also run it in Xcode 8.3, but you need to install the latest Swift 4.0 snapshot from swift.org (don’t worry, it’s easy).

Screenshot of the playground in Xcode 8.3