Sixth Printing March, 2016

Typos, formatting errors, etc:

  • Page 42: Third paragraph, first line; dependences, should be dependencies. 

Fifth Printing March, 2015

Typos, formatting errors, etc:

  • Page 42: Line 22, the apostrophe in "that's" is inverted.
  • Page 33: It's vs Its. Sentence should read, "It's time to set Wheel free to be a separate class of its own."

Fourth Printing September, 2014

Second and Third Printing  March and November, 2013

Typos, formatting errors, etc:

  • Page 35: Line 3 from bottom, ‘know something know about’ should be ‘know something about’.
  • Page 42: Line 11 from top, ‘dependences’ should be ‘dependencies’.
  • Page 42: Line 20 Daniel Hüsch, from top, ‘dependences’ should be ‘dependencies’.
  • Page 54: Line 15 from top, ‘Gear suddenly begin to’ should be ‘began to’.
  • Page 63: Line 19 from top, ‘a new tool aid to’ should be ‘a new tool to aid’.
  • Page 121: Last Line, ‘in common in now’ should be ‘in common is now’.
  • Page 130: Line 4 from top, ‘parts up the Bicycle’ should be ‘parts up to Bicycle’.
  • Page 144: Line 14 from top, ‘works it way’ should be ‘works its way’.
  • Page 144: Line 8 from bottom, ‘that a object is’ should be ‘that an object is’.
  • Page 145: Figure 7.1, ‘starting + lead_days’ should be ‘starting – lead_days’
  • Page 146: Figure 7.2, ‘starting + lead_days’ should be ‘starting – lead_days’
  • Page 161: Line 5 from bottom: ‘thought of a pyramid’ should be ‘thought of as a pyramid’.
  • Page 179: Line 10, ‘PartFactory’ should be ‘PartsFactory’.
  • Page 185: Line 12 from bottom, ‘easy way do so’ should be ‘easy way to do so’.
  • Page 202: Line 4 from bottom, ‘You application is’ should be ‘Your application is’.
  • Page 214: Line 17 from top, ‘methods into new object’ should be ‘methods into a new object’.
  • Page 235: Line 8 from bottom, ‘difficult and impossible’ should be ‘difficult to impossible’.

First Printing  September 5, 2012

Errors in content or code:

  • Page 43: Both examples should have an attr_reader for :wheel.
  • Page 48: In the first full sentence on the page the word ‘multiplies’ should replaced by ‘divides’.  This discussion is about argument order dependencies; division has a dependency on order but multiplication does not.
  • Page 182: The comments in the code listings should NOT reference class PartsFactory::Part.  The Part class has been removed.
  • Page 231: Line 19 of the code sends the wrong message.  It should read assert_respond_to(@object, :tire_size)

Typos, formatting errors, etc:

  • Page 11: Line 7, ‘effects’ should be ‘affects’.
  • Page 11: Line 13, ‘repayed’ should be ‘repaid’.
  • Page 17: Line 3, ‘distant code relies’ should be ‘distant code that relies’.
  • Page 27: Line 2, ‘milimeters’ should be ‘millimeters’.
  • Page 35: Line 3 from bottom, ‘know something know about’ should be ‘know something about’.
  • Page 66: Figure 4.3, ‘need bike’ should be ‘need_bike’.
  • Page 75: Figure 4.8, ‘need bike’ should be ‘need_bike’.
  • Page 75: Figure 4.8, ‘route type’ should be ‘route_type’.
  • Page 76: Line 6 from bottom, “it’s” should not contain an apostrophe.
  • Page 79: Line 14 from bottom, ‘what verses how’ should be ‘what versus how’.
  • Page 79: Line 9 from bottom, “it’s” should not contain an apostrophe.
  • Page 80: Line 12 from bottom, ‘Demeter become a’ should be ‘Demeter became a’.
  • Page 108: Line 1, comma following spares.size should be in the proportional font.
  • Page 110: Line 6 of the code, ‘@type’ should be ‘@style’.
  • Page 112: Line 3, comma Bicycle’s should be in the proportional font.
  • Page 113: The first word of the last paragraph should be ‘The’ instead of ‘That’.
  • Page 113: Figure 6.3, ‘supercalss’ should be ‘superclass’.
  • Page 121: Last Line, ‘in common in now’ should be ‘in common is now’.
  • Page 128: In the sentence ‘Once Bicycle provides this implementation of default_tire_size’, ‘default_tire_size’ should be in the code font.
  • Page 138: Line 24 of the code, ‘10-speed’ should be ‘9-speed’.
  • Page 142: Line 12 from bottom, the comma after ‘customers’ should be in the proportional font.
  • Page 144: Line 14, ‘works it way’ should be ‘works its way’.
  • Page 144: Line 8 from bottom: ‘that a object is’ should be ‘that an object is’.
  • Page 145: Figure 7.1, ‘starting + lead_days’ should be ‘starting – lead_days’
  • Page 146: Figure 7.2, ‘starting + lead_days’ should be ‘starting – lead_days’
  • Page 147: Line 2, the ’s’ at the end of ‘Schedulables’ should be in the proportional font.
  • Page 152: Line 2, the comma after ‘lead_days’ should be in the proportional font.
  • Page 155: Line 12, ‘sending it new message’ should be ‘sending it a new message’.
  • Page 156: Line 12, ‘that is does’ should be ‘that it does’.
  • Page 157: In figure 7.7, ‘modues’ should be ‘modules’.
  • Page 159: Line 7, ‘confident than because’ should be ‘confident that because’.
  • Page 161: Line 5 from bottom: ‘thought of a pyramid’ should be ‘thought of as a pyramid’.
  • Page 179: Line 10, ‘PartFactory’ should be ‘PartsFactory’.
  • Page 185: Line 12 from bottom, ‘easy way do so’ should be ‘easy way to do so’.
  • Page 187: Line 2 from bottom, ‘Idential delegation code many’ should be ‘Identical delegation code may’.
  • Page 187: Line 8 from bottom, ‘Compsitions’ should contain an apostrophe.
  • Page 188: Line 17, “it’s” should not contain an apostrophe.
  • Page 202: Line 4 from bottom, ‘You application is’ should be ‘Your application is’.
  • Page 205: Line 3, ‘Goal of this test is ensure’ should be ‘Goal of this test is to ensure’.
  • Page 207: Line 10, the apostrophe in Diameterizable’s should be in the proportional font.
  • Page 211: Line 10, ‘alternations’ should be ‘alterations’.
  • Page 216: Line 4, the comma following ‘self’ should be in the proportional font.
  • Page 218: Line 8 from bottom, the apostrophe in observer’s should be in the proportional font.
  • Page 219: Line 13, the comma following TripCoordinator should be in the proportional font.
  • Page 233: Line 2, the s at the end of Bicycles should be in the proportional font.
  • Page 234: Line 5, the s at the end of MountainBikes should be in the proportional font.
  • Page 235: Line 8 from bottom, ‘difficult and impossible’ should be ‘difficult to impossible’.

If you find errors, please send details via email.

Thanks to Patrik Bóna, Eric Bouchut, Trevor Bramble, Mathhew Boedicker, Steve Downie, Mike Cook, Daniel Hüsch, Jonathan Kern, Rich Morin, Henrik Nyh, Alex Perkins, Marcus Stollsteimer, Tekin Suleyman, Yannick Voyer, @nassersala, @robi-y, @tomjoro, Matthew Ewell, Damian Rossney, and Angelos Orfanakos for reporting errors.

(If you’re not on this list but should be, my apologies, and please let me know.)