Errata

The line entered as "Besides a type, a variable needs a name so that you can use that name in code." in the 7th paragraph of chapter 3 is reentered in the 9th paragraph of chapter 3 as "Besides a type, a variable needs a name so that you can use that name in code.".

Note from the Author or Editor:
Error not present in the printed book, or in the PDF version I'm looking at, however it is present in the O'Reilly learning platform version.

The first instance of "Besides a type, a variable needs a name so that you can use that name in code." should be removed. Only the second one, between the two highlighted callouts, is required.

Section: Just the new stuff: #1 mentioned "break" see #4 below and it should be, see #3 below. There is no #4 in the code or in the image.

Text: Sharpen your pencil (from page 14)
Erratum: exercise is actually on page 15
Suggested fix: change "page 14" to "page 15"

`boolean isLearning;` is described as "declare a boolean named isCrazy [sic] (no assignment".

`isLearning = true;` is described as "assign the value true to the previously declared isCrazy [sic]"

Note from the Author or Editor:
Text should read:

declare a boolean named isLearning (no assignment)
assign the value true to the previously declared isLearning

redundant closing ), either after "a cell" or after "etc.".

Note from the Author or Editor:
Remove the ")." after 'as "A3", "C5", etc.'

The correct output i.e `13 15 i = 6` is missing.

Note from the Author or Editor:
True. The terminal outputs need changing from "x" to "i":

12 14 x = 6 should be 12 14 i = 6
13 15 x = 6 should be 13 15 i = 6

Inconsistent use of <<true>> (without quotes) vs "true" (with quotes):

contains(Object o)
Returns true if this list contains the specified element.

isEmpty()
Returns “true” if the list contains no elements.

Suggested fix: remove quotes from isEmpty() explanation, since return value is a boolean, not a string.

Note from the Author or Editor:
Agree, remove quotes from isEmpty explanation

Original: "You declare the type of the array using a type parameter, which is a type name in angle brackets. Example: ArrayList<Button> ……"
Problem: Usage of "type of array" could be misleading.
Possible fix: Change text to: "You declare the type of the ArrayList using a type parameter, which is a type name in angle brackets. Example: ArrayList<Button> ……"

Original: "Note: if you already know printf() from c/C++, you can probably ..."
Problem: Tiny typo: "c/C++": c should be uppercase
Solution: Write as "C/C++"

Text: the songDB ArrayList was declared on the last page.
The text should read: the songs ArrayList was declared on the last page.

Original text: Pass a List<Animal> into our testAnimals method
It should read: Pass a List<Animal> into out takeAnimals method

Original Text: Will this work now that we changed from an array to a List?
It should read: Will this work now that we changed from a List<Animal> to a List<Dog>?

Note from the Author or Editor:
Should be "Will this work now that we have changed from a List<Animal> to a List<Dog>?"

Original text: the catch argument is declared as type Exception, and the parameter reference variable is ex.

It should read: the catch argument is declared as type Exception, and the parameter reference variable is e.

Note from the Author or Editor:
Confirmed. Should say "e" in the text.

Box title "metacognitive tip" is set in a different font than on pages 33 and 108.

Note from the Author or Editor:
Confirmed. However, formatting in Head First Java is intentionally not consistent. Correcting to use the same font as 33 and 108 is nice but not mandatory.

Original text: This is the Big Important Graphics method.

It should say: This is the Big Important paintComponent method.

Note from the Author or Editor:
It's not necessarily incorrect, but it's also not very clear. It's meant to mean this is the important method for drawing graphics. It's from JComponent, it's not super clear whether the important thing is the method and where it's from, or if it's the parameter Graphics which is important. I would reword this to:

"This is the Big Important drawing method."

Or even simply "This is the Big Important method."

Original: // See page 365 for the code
Problem: Code is actually on page 473
Solution: Change "page 365" to "page 473"

Original: page heading reads: "object lifecycle"
Problem: The contents of the page refers to usage of lambdas instead of inner classes
Suggestion: Maybe a heading matching the contents might be a better choice.

Note from the Author or Editor:
Agree that "object lifecycle" is incorrect. I would change to "inner classes as lambdas".

Original: do this for each of the 16 ROWS (i.e., Bass, Congo, etc.)
Problem: Congo is a country
Solution 1: Specify if you mean République du Congo or République démocratique du Congo
Solution 2: Correct to “Conga” (the percussion instrument)

:)

Note from the Author or Editor:
Congo should be "Conga"

Original: 8. Romulin command
Problem: The extraterrestrial race who use a cloaking device for their "birds of prey" are called "Romulans".
Solution: Ask a Trekkie. Change "i" to "a".

Original Text: FTP? 20.

Should be: FTP? 21.

Note from the Author or Editor:
Correct, it should be 21

Original: The JVM switches between the new thread (user thread A) and the original main thread, until both threads complete.

Problem: Caption on figure next to #3 says, 'user thread "t"'

Possible fix: Change text in parentheses to (user thread "t") for consistency.

Note from the Author or Editor:
Yes, text should be (user thread "t")

Error: annotations are pointing to the wrong dumpStack() call output in the terminal image.

Fix: "dumpStack() called from doMore() in MyRunnable" annotation should point to the output in the terminal that "dumpStack() called from main() method" annotation is pointing to.

Note from the Author or Editor:
Oh my God it's true. Yes.

Annotation "dumpStack() called from doMore() in MyRunnable" should point to the BOTTOM stack trace.

Annotation "dumpStack() called from main() method" should point to the TOP stack trace.

Error: the output in the terminal that says "Sorry Monica, you can't buy this" should be "Sorry Monica, you haven't spent the money." to match what the previous code example will print in that case.

Original: NETWORKING: Just like the SimpleChatClient in this chapter, the BeatBox now connects to the server and gets an input and output stream.

Problem: The most current version of the SimpleChatClient is in chapter, not the appendix.

Possible fix: Change prose to: NETWORKING: Just like the SimpleChatClient in chapter 17, the BeatBox now connects to the server and gets an input and output stream.

Note from the Author or Editor:
Agree with suggested fix.

Original: This layout manager one lets you [...].

Problem: 'one' has no context.

Suggested fix: Omit 'one'

Note from the Author or Editor:
Confirmed: delete "one"

Original: not equals (!equals and !) 151

Problem: "!equals" should really be "!="

Fix: not equals (!= and !) 151

Note from the Author or Editor:
Should indeed be !=