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.

The latest version of the book is P2.0, released 27 days ago. If you've bought a PDF of the book and would like to upgrade it to this version (for free), visit your home page.

Key: Typo Tech. Error Suggestion Not a problem Next edition

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PDF Paper Description Found in Fixed in
xi
#76532: Remove the Forward to the 3rd edition. It makes the 1.9/2.0 version which is 4th ed appear to be the 3rd edition and confuses customers. Espec...more...
P1.0
13-Mar-14
5

#76356: "... is Luis Lavena's RubyInstaller.org." ->

"... is Luis Lavena's RubyInstaller."--Jon Forrest

P1.0
02-Feb-14
11

#53158: "(To get a list of classes with ri documentation, type
ri with no arguments.)"
Isn't that what -l (--list) switch is for?--Anatoly Kamchatnov

P1.0
16-Nov-13
62
#76433: I have following version of ruby. asang@speedy ruby]$ ruby -v ruby 2.0.0p353 (2013-11-22 revision 43784) [x86_64-linux] When I try usin...more...
P1.0
17-Feb-14
90
#76576: In the following code on page 90: class Person include Comparable attr_reader :name def initialize(name) @name = name end def to_s "...more...
P2.0
28-Mar-14
114
#53155: In "Table 2—Character class abbreviations" \s Whitespace (?a), (?d) → [␣\t\r\n\f] (?a), (?d) → [0-9] This seems to be suggesting ...more...
P1.0
15-Nov-13
298

#76355: Unlike their lowercase counterparts, %I, %Q, and %W will preform interpolation:

should be 'perform'--Patrick Neve

P1.0
31-Jan-14
320
#76489: The description of Ranges in Boolean Expressions contains errors, is confusing, and really ought to be rewritten! Both the logic of this expr...more...
P1.0
06-Mar-14
338
#76394: Private methods therefore can be called in the defining class and by that class’s descendents and ancestors, but only within the same object. ...more...
B2.0
09-Feb-14
429

#76663: Chapter 27's coverage of the Array class is missing ".include?", and the index for ".include?" also doesn't mention that it applies to arrays.--Ken Ebling

P2.0
15-Apr-14
438

#57977: Sample invocation of Array#unshift contains a right curly brace that should be left out.--Meindert Meindertsma

P1.0
25-Dec-13
585

#76320: The example code in Module#prepend documentation is truncated.--Rafal Rzepecki

P1.0
21-Jan-14
763

#53282: "when the file cn be read or written" -> "when the file can be read or written"--Graham Menhennitt

P1.0
05-Dec-13