The errata list is a list of errors and their corrections that were found after the product was released. If the error was corrected in a later version or reprint the date of the correction will be displayed in the column titled "Date Corrected".
The following errata were submitted by our customers and approved as valid errors by the author or editor.
Color key: Serious technical mistake Minor technical mistake Language or formatting error Typo Question Note Update
| Version |
Location |
Description |
Submitted By |
Date submitted |
Date corrected |
| Printed |
Page 38
3rd paragraph |
The sentence:
"Be aware that if you use a variable name that already exists in the containing scope, the block assigns that variable each successive value, which may or may not be what you want."
Should read:
"Be aware that, previous to 1.9, if you use a variable name that already exists in the containing scope, the block assigns that variable each successive value, which may or may not be what you want."
Note from the Author or Editor:
This is correct. Change the paragraph to read: "Be aware that, previous to 1.9, if you use a variable name that already exists in the containing scope, the block assigns that variable each successive value, which may or may not be what you want." |
Mike Fitzgerald |
Sep 02, 2015 |
Oct 23, 2015 |
| Other Digital Version |
42
"Negation" paragraph |
Under "Conditional Statements", "The if Statement", then "Negation", the text says :
"The negation operator ! reverses the true/false value of its expression:", which is true, but then give these two examples:
"if !x == y then puts 'x does not equal y' end"
and
"if !x > y
puts 'x is not greater than y'
end"
These two examples are wrong and false. The operator ! has the highest precedence, so it only applies to x in both examples.
The examples would be valid only if
1) parentheses would be added, like "if !(x == y)" and "if !(x > y)", or
2) the 'not' operator would be used, like "if not x == y" and "if not x > y"
as, contrary to the ! operator, the "not" operator has the lowest precedence.
Note from the Author or Editor:
On page 42, add parentheses to:
if !x == y then puts 'x does not equal y' end
change to
if !(x == y) then puts 'x does not equal y' end
and change
if !x > y
puts 'x is not greater than y'
end
to
if !(x > y)
puts 'x is not greater than y'
end
|
Anonymous |
Mar 16, 2016 |
|
| Other Digital Version |
64
Paragraph above Table 1-8. Files modes |
The text says:
"The first argument to 'new' names the new file 'file.rb', and the second argument specifies the file mode: 'r' for readable, 'w' for writable, or 'x' for executable."
'x' is not even a valid value for the 'mode' parameter (see table 1-8, or ruby documentation).
Note from the Author or Editor:
This is correct. The paragraph should now read exactly like this:
The first argument to new names the new file file.rb, and the second argument specifies the file mode. The effects of the different modes are shown in #file_modes. |
Anonymous |
Mar 16, 2016 |
|
| PDF, ePub |
Page 167
Second code example, top of page, definition of month_list |
In the example defining month_list, there is an extraneous extra quote. :oct"=>"October" should not have the quote after :oct and should read :oct=>"October". This is likely in the printed version too.
Note from the Author or Editor:
Correct. On page 167, delete the double quote following :oct—
:oct" => "October",
should be
:oct => "October", |
Matthew Halverson |
Feb 24, 2016 |
|