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The latest version of the book is P3.0, released over 3 years ago. If you've bought a PDF of the book and would like to update it to this version (for free), visit your home page.

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  • Typo
  • Tech. error
  • Suggestion
  • Maybe next edition
  • Not a problem
  • Reported in: P1.0 (11-Oct-17)
PDF page: ¨82
In the Safari Books Online edition (no page numbers available), Chapter 3, Quiz: Bug Hunt, the sample output is: 5...​  6... ​  10... ​  Bob go...more...
Paolo Perrotta says: I cannot believe nobody spotted this so far. Thank you! If we have another printing, I will fix it.
  • Reported in: P3.0 (18-Nov-17)
PDF page: 49
The Pry example is not behaving as advertised. Pry instances do not have a quiet= method, nor do they have a refresh method. Is there a specific ver...more...
Paolo Perrotta says: Hey, Peter! I used Pry version, which is the version that you will find in the book's source code, under the 'gems' directory. (Ruby libraries typically change fast, so I expect that some examples became obsolete soon after the book came out. To make it easier for readers to make their own experiments, I packaged the versions of gems that I used in the book with the rest of the examples.)
  • Reported in: P3.0 (18-Jun-17)
PDF page: 193
The writer is describing the "save_with_validation!" and mistakenly reuse the name again when what he meant was "save_without_validation!". This is ...more...
Paolo Perrotta says: Thanks, Bolatan! I'll submit this for the next printings, if we get any more.