We try to keep our books accurate, but sometimes mistakes creep in. This page lists the errors submitted by our astute readers. If you've found a new error, please submit it.

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PDF Paper Description Found in Fixed in
29
#30570: you should add the "Ruby One-Click Installer for Mac OSX" to your list of osx ruby distributions. see the project on rubyosx.com -- furthermor...more...
 B1.03
37

#34022: code illustrating "shebang" includes puts "Hello, world!", but the output shown is "It is now.......

may be confusing to new folk--Al Thomas

 B1.09
60
#34138: Integer(price * 100) Price = 33.8 Price in cents = 3379 To me this just seems wrong. If I am a store owner I would loosing money here... ...more...
 B1.10
60
#33198: It looks like you're trying to keep a clean set of numbered "tutclasses_##.rb" files. But it seems a little strange that we have a java class ...more...
 B1.09
65
#33199: It looks like you're trying to have a cleanly numbered set of "tutclasses_##.rb" files, but in the example on this page we're calling the file...more...
 B1.09
72

#33046: The bookmark "Inheritance and Messages" does not lead to that section on page 72 but links to the box "Inheritance and Mixins" on page 78

 B1.09
73
#33590: My problem may well be that I am still running 1.8.6, but I can't see why c.say_hello would return two responses. In 1.8.6 at least, it only r...more...
 B1.09
91

#34147: Middle paragraph: "...and a block parameter (arguments starting with an ampersand)."
Should "arguments" be plural or singular here?--Charlie O'Keefe

 B1.10
94

#34144: Near bottom: duplicate duplicate "that that"--Charlie O'Keefe

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101

#34145: Footnote 6: Should "conventially" be "conventionally"?--Charlie O'Keefe

 B1.10
141

#34149: Toward end: "Arrays, support this:"
Should this be, "Arrays support this:" (without the comma)?--Charlie O'Keefe

 B1.10
152

#34126: "As of Ruby 1.9, his is no longer supported."
should be
"As of Ruby 1.9, this is no longer supported."
--Kyo Endo

 B1.10
152
#34152: Last paragraph: "The === operator is defined in Class to test if the argument is an instance of the receiver or one of its superclasses." T...more...
 B1.10
157

#34151: Paragraph in middle of page: "they typically make most sense when..."
How about: "they typically make THE most sense when..."--Charlie O'Keefe

 B1.10
204
#34154: 3rd paragraph: "you can even mix Shoulda tests for regular test::Unit test methods." How about: "you can even mix Shoulda tests into regular ...more...
 B1.10
204

#34176: In the first line, it should be 'user stories' instead of 'user stores'--Stefan Lembach

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205

#34133: In the first full paragraph on the page, fourth sentence, unlike LIFE not like.--David Johnson

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208
#34130: Word missing in first paragraph after "Anyone for Shoulda?": You [word missing] much of the descriptive power of RSpec-style expectations wit...more...
 B1.10
208

#34131: "Should" should be "Shoulda" in second paragraph under "Anyone for Shoulda?":
Install Should[a] using gem install Shoulda.--Dirk Groten

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209

#34155: Near bottom: "[1, 9 in t.rb"
Looks like it's missing a closing bracket...--Charlie O'Keefe

 B1.10
211

#34172: "so I;d recommend a quick web search rather.. "
should be "so I'd recommend a quick web search rather.."

--Kyo Endo

 B1.10
234

#34174: "HEre we can just use rm"
should be "Here we can just use rm"--Kyo Endo

 B1.10
242

#34175: ".. options.rb file inslde a directory named anagram.."
should be ".. options.rb file inside a directory named anagram"--Kyo Endo

 B1.10
243
#34157: Footnote 3: "We talk about Shoulda starting on page ??. For now, you can run this code by installing the gem using gem install Shoulda." I ...more...
 B1.10
245

#34158: Top of "require_relative and Ruby 1.8" sidebar: "you can use still use" (extra 'use' in there)--Charlie O'Keefe

 B1.10
247

#34159: "Now all our files are in place, we can..."
How about:
"Now THAT all our files are in place, we can..."--Charlie O'Keefe

 B1.10
250
#34160: 4th-to-last paragraph: "The s.executables line tells Gems to install the anagram command-line script the Gem gets installed on a user's machin...more...
 B1.10
253

#34185: "Tama" sounds strange to me for a Japanese female name, but for a Japanese cat's name. Mai, Hana, Yui are much better... I dont know...--Kyo Endo

 B1.10
255

#34162: Near end of "Source Files" section: "For UTF-8. If Ruby sees the byte sequence..."
I'm guessing this should be a comma after "For UTF-8"?--Charlie O'Keefe

 B1.10
295

#34198: The description for CGI.escapeElement says; "Here only the A element is escaped; other elements are left alone." but <hr> element is also escaped.--Kyo Endo

 B1.10
302

#34164: First paragraph: "...as if the template is eing evaluated..."
Change "eing" to "being"--Charlie O'Keefe

 B1.10
376
#34268: (for example, by invoking items.size, the process is surprisingly similar. should be (for example, by invoking items.size), the process is...more...
 B1.10
376

#34287: "The ony change—and it’s a vitally important one" should say "The only change—and it’s a vitally important one"--Stephen Anderson

 B1.10
391

#34284: sample code uses attr_reader for defining an accessor method. But I feel that using instance_variable_get method is appropriate in this context.--Kyo Endo

 B1.10
428
#32757: In the table of contents, the “Array” and similar sections are on the same level than the “Built-in Classes and Modules” section, thus, it is ...more...
 B1.09
447

#34171: in frozen?
"or it it is in" should be "or if it is in"--David Barta

 B1.10
453

#34274: Appear to be missing 'sort' (have 'sort!), and 'sort_by' methods.--Garold L Johnson

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480

#34275: 'each_with_index' overlaps the description (at least in the pdf).--Garold L Johnson

 B1.10
534
#34210: In the first sentence on page 534 there is a double 'an': "Modes can be represented an an integer formed by or-ing together values from Tab...more...
 B1.09
541
#34211: Description of each_byte needs to be separated into two lines. Line reads: "io.each_byte {| byte | block } →nilio.each_byte → enum" but sho...more...
 B1.09
549
#34253: In the IO#gets section, you have this sentence:(although the setting of $_ is considered ugly, an may be removed in future). The word "an" is ...more...
 B1.10
685

#34288: In 1.8, 'members' returns an array of strings rather than an array of symbols. Does this change in 1.9?--Garold L Johnson

 B1.10
728

#34195: If has a
few incompatibilities with the original.

should read:

It has a
few incompatibilities with the original.--Stephen Anderson

 B1.10
781
#30437: Chapter 28 (extending ruby) doesn't discuss the treading model in 1.9, and the big VM lock. I think this is a big change, and should be addres...more...
 B1.03
791

#34289: 'tuples may be matched using regular expressions, the classes of their elements,' s/b '...expressions, or ...'--Garold L Johnson

 B1.10