This contains some sample code in Swift and there explanations in comments.

To be able to view it properly with code and outputs, download the zip into your desktop, and then open the Plawan_Learn.playground file. The file should open in Xcode. Make sure that you are using Xcode 6 or above which supports swift. Also, this file contains most of the examples given in the book by Apple, but also contains some experiment code which helped me understand some of the stuff. Hope its helpful....