I just downloaded the sample code to review before digging into the book. It seems that there are several issues in the sample code that cause crashes. Is that intentional?
In general no. However, swift is fairly quickly moving and it is quite possible that some of the code has become out of date from the time it was written to the current version of Xcode. If you add the issues to errata it would help them get sorted and corrected.
I think the code is not updated to Swift 2.2. I’m getting lots of issue. Please update the code as I already bought the book.