I think I just found an error in Chapter 8 (the ePub version, so this could just be to do with how it renders the text on my iPad screen).
In 2 code examples, the book references the line:
IBOutlet NSTextField *newItemName-TextField;
but it doesn’t work unless you remove the hyphen:
IBOutlet NSTextField *newItemNameTextField;
(looking more carefully, I think it’s just iBooks adding hyphens when the line overspills. But only a few overspilling lines have hyphens. Is there some “don’t do hyphens” code in the ePub file that’s missing on this occasion?)