p.9, ¶2: for "can compared", read "can be compared". (Thanks to Antonio Macías Ojeda, 2015-10-22. Corrected in the second printing.)
p.13: As printed, the gopl.io/ch1/lissajous program is deterministic, not random. We've added the statement below to the downloadable program so that it prints a pseudo-random image each time it is run. (Thanks to Randall McPherson, 2015-10-19.)
rand.Seed(time.Now().UTC().UnixNano())
p.15, ¶2: For "inner loop", read "outer loop". (Thanks to Ralph Corderoy, 2015-11-28. Corrected in the third printing.)
p.19, ¶2: For "Go's libraries makes", read "Go's library makes". (Thanks to Victor Farazdagi, 2015-11-30. Corrected in the third printing.)
p.40, ¶4: For "value of the underlying type", read "value of an unnamed type with the same underlying type". (Thanks to Carlos Romero Brox, 2015-12-19.)
p.40, ¶1: The paragraph should end with a period, not a comma. (Thanks to Victor Farazdagi, 2015-11-30. Corrected in the third printing.)
p.43, ¶3: Import declarations are explained in §10.4, not §10.3. (Thanks to Peter Jurgensen, 2015-11-21. Corrected in the third printing.)
p.48: f.ReadByte() serves as an example of a reference to f, but *os.File has no such method. For "ReadByte", read "Stat", four times. (Thanks to Peter Olsen, 2016-01-06. Corrected in the third printing.)
p.52, ¶2: for "an synonym", read "a synonym", twice. (Corrected in the second printing.)
p.52, ¶9: for "The integer arithmetic operators", read "The arithmetic operators". (Thanks to Yoshiki Shibata, 2015-12-20.)
p.68: the table of UTF-8 encodings is missing a bit from each first byte. The corrected table is shown below. (Thanks to Akshay Kumar, 2015-11-02. Corrected in the second printing.)
0xxxxxxx runes 0−127 (ASCII)
110xxxxx 10xxxxxx 128−2047 (values <128 unused)
1110xxxx 10xxxxxx 10xxxxxx 2048−65535 (values <2048 unused)
11110xxx 10xxxxxx 10xxxxxx 10xxxxxx 65536−0x10ffff (other values unused)p.73, ¶1: For "a exercise", read "an exercise". (Thanks to vrajmohan, 2015-12-28.)
p.74: the comment in gopl.io/ch3/printints should say fmt.Sprint, not fmt.Sprintf. (Corrected in the second printing.)
p.75, ¶4: for "%u", read "%o". (Thanks to William Hannish, 2015-12-21.)
p.76: the comment // "time.Duration 5m0s should have a closing double-quotation mark. (Corrected in the second printing.)
p.79, ¶4: "When an untyped constant is assigned to a variable, as in the first statement below, or appears on the right-hand side of a variable declaration with an explicit type, as in the other three statements, ..." has it backwards: the first statement is a declaration; the other three are assignments. (Thanks to Yoshiki Shibata, 2015-11-09. Corrected in the third printing.)
p.112: Exercise 4.11 calls for a "CRUD" (create, read, update, delete) tool for GitHub Issues. Since GitHub does not currently allow Issues to be deleted, for "delete", read "close". (Thanks to Yoshiki Shibata, 2016-01-18.)
p.115: The anchor element in gopl.io/ch4/issueshtml's template is missing a closing </a> tag. (Thanks to Taj Khattra, 2016-01-19.)
p.132, code display following ¶3: the final comment should read: // compile error: can't assign func(int, int) int to func(int) int (Thanks to Toni Suter, 2015-11-21. Corrected in the third printing.)
p.160, ¶4: For Get("item")), read Get("item"). (Thanks to Yoshiki Shibata, 2016-02-01.)
p.166, ¶2: for "way", read "a way". (Corrected in the third printing.)
p.200, TestEval function: the format string in the final call to t.Errorf should format test.env with %v, not %s. (Thanks to Mitsuteru Sawa, 2015-12-07. Corrected in the third printing.)
p.222, Exercise 8.1: The port numbers for London and Tokyo should be swapped in the final command to match the earlier commands. (Thanks to Kiyoshi Kamishima, 2016-01-08.)
p.272, ¶3: for "the request body", read "the response body". (Thanks to 曹春晖, 2016-01-19.)
p.288, code display following ¶4: In the import declaration, for "database/mysql", read "database/sql". (Thanks to Jose Colon Rodriguez, 2016-01-09.)
p.347, Exercise 12.8: for "like json.Marshal", read "like json.Unmarshal". (Thanks to chai2010, 2016-01-01.)
p.362: the gopl.io/ch13/bzip program does not comply with the proposed rules for passing pointers between Go and C code because the C function bz2compress temporarily stores a Go pointer (in) into the Go heap (the bz_stream variable). The bz_stream variable should be allocated, and explicitly freed after the call to BZ2_bzCompressEnd, by C functions. (Thanks to Joe Tsai, 2015-11-18. Corrected in the third printing.)