Head First Go

Errata for Head First Go

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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
Safari Books Online
Ch 14
We’ve introduced a bug!

Under the image of a construction worker there are two "checks" with text like: "For []slice{"apple", "orange", "pear"}, JoinWithCommas should return "apple, orange, and pear"" I guess it should be []string{...} instead in both of them.

Note from the Author or Editor:
Change all occurrences in chapter of "[]slice" to "[]string" (without quotes). Affected pages are 405, 409, and 412.

Balazs Jakab  Apr 23, 2019  Jul 26, 2019
Safari Books Online
Ch 8
Struct field names must be capitalized to be exported

The text contains fields that are not - yet - added to the scruct: "It wouldn’t make sense to be able to access the subscription rate from other packages, but not the name or address." Maybe should refer to "active" field instead: "It wouldn’t make sense to be able to access the subscription rate from other packages, but not the name or active."

Note from the Author or Editor:
Change this sentence: It wouldn’t make sense to be able to access the subscription rate from other packages, but not the name or address. To this: It wouldn’t make sense to be able to access the subscription rate from other packages, but not the name or active status.

Balazs Jakab  Apr 21, 2019  Jul 26, 2019
Safari Books Online
Ch 8
Pass large structs using pointers

This text most probably contains a typo: "Since this is already a struct, remove the address-of operator" I guess it should be something like: "Since this is already a pointer, remove the address-of operator"

Note from the Author or Editor:
Confirmed. Annotation should be updated as described in submission.

Balazs Jakab  Apr 21, 2019  Jul 26, 2019
Safari Books Online
Ch 6
Slices and zero values

The output and code fragment do not match. Code: intSlice = append(intSlice, 27) fmt.Printf("intSlice: %#v\n", intSlice) Output: stringSlice: []string{27} The output should be: intSlice: []int{27}

Note from the Author or Editor:
Confirmed. Output text should be updated as described in submission.

Balazs Jakab  Apr 21, 2019  Jul 26, 2019
Safari Books Online
Ch 1
Math operations and comparisons

In the book it's written like this: "<= tests whether the second value is less than or equal to the first, and >= tests whether the second value is greater than or equal to the first." I guess it's the other way around, so should be: ">= tests whether the second value is less than or equal to the first, and <= tests whether the second value is greater than or equal to the first."

Note from the Author or Editor:
On page 13, "<= tests whether the second value is less than or equal to the first, and >= tests whether the second value is greater than or equal to the first" should be changed to "<= tests whether the first value is less than or equal to the second, and >= tests whether the first value is greater than or equal to the second".

Balazs Jakab  Apr 16, 2019  Jul 26, 2019
Safari Books Online
Ch 11
Under "A method parameter that can only accept one type"

https://imgur.com/a/pDK4iIE

Note from the Author or Editor:
The annotation "TapePlayer also has a Play method with a string parameter" should be changed to "TapeRecorder also has a Play method with a string parameter". The annotation "TapePlayer also has a Stop method with no parameters" should be changed to "TapeRecorder also has a Stop method with no parameters".

Mahmudul Haque  Jan 27, 2019  Jul 26, 2019
Safari Books Online
1st paragraph in chapter “8 structs” (page number unknown, Safari Books Online does not display page numbers)

The phrase “Think of mailing addresses, where you have to mix street names (strings) with postal codes (integers).” recommends bad practices: Postal codes should not be represented by integers, but by strings (of digits). First of all, in many countries (including e.g. the U.S.) postal codes may contain leading zeros. In such countries a postal code 01234 is not at all the same as 1234. More importantly, it is semantically wrong: Integers are intended to represent entities with which calculations can be done. It does not make sense to add or multiply postal codes. Postal codes are just strings that happen to consist of digits, but their numeric value has no meaning.

Note from the Author or Editor:
In the Chapter 8 introduction, change "Think of mailing addresses, where you have to mix street names (strings) with postal codes (integers)" to "Think of billing receipts, where you have to mix item names (strings) with quantities (integers)".

Martin Dickopp  Oct 30, 2018  Jul 26, 2019