Errata

CHANGE FROM

Because Sun (now Oracle) had a trademark on the word _Java_, the official name of the language to be standardized couldn’t be _JavaScript_.

TO

Because Sun (now Oracle) had a trademark on the term _JavaScript_, it couldn’t be the official name of the language to be standardized.

CHANGE

In early December 1995, Java’s momentum had grown, and Sun licensed the trademark Java to Netscape. The language was renamed again, to its final name, JavaScript.

TO

In early December 1995, Java’s momentum had grown and the language was renamed again, to its final name, JavaScript.

"there is a trademark on _Java_" -> "there is a trademark on _JavaScript_"

"Number: -0, NaN"

should read

"Number: 0, NaN"

or

"Number: 0, -0, NaN"

as 0 makes more since than -0, conceptually.

Note from the Author or Editor:
The first way to fix this is best (as I’m usually pretending that there’s only a single zero).

"All values in JavaScript have properties" should read "Most values in JavaScript have properties".

null and undefined are two values which do not have properties. Each is the single value of its own type. That is type Null has one value null that does not have properties. Also, type Undefined has one value undefined which does not have properties.

Note from the Author or Editor:
I don’t want to make things too complicated, but a footnote is in order. Thus: At the end of the sentence "All values in JavaScript have properties", add the following footnote: "The two “non-values” `undefined` and `null` do not have properties."

var jane = Object.create(PersonProto);
jane.value = 'Jane';

->

var jane = Object.create(PersonProto);
jane.name = 'Jane';

Note from the Author or Editor:
Yes. Correction exactly as mentioned in the description of the error (first of the two lines stays the same):

var jane = Object.create(PersonProto);
jane.value = 'Jane';

->

var jane = Object.create(PersonProto);
jane.name = 'Jane';

iBooks version, 'page' 282 of 966, end of Ch 12.

Demonstrating replacement via regex, the following example has an incorrect second line:

> function repo(all) { return '('+all.toUpperCase()+')' }
> 'axbbyyxaa'.repl(/a+|b+/g, replacement)
'(A)x(BB)yyx(AA)'

I think you meant something like the second line, below:

> function repl(all) { return '(' + all.toUpperCase() + ')' }
> 'axbbyyxaa'.replace(/a+|b+/g, repl)
'(A)x(BB)yyx(AA)'

Note from the Author or Editor:
Correct! Change the second line in the code snippet. FROM

> 'axbbyyxaa'.repl(/a+|b+/g, replacement)

TO

> 'axbbyyxaa'.replace(/a+|b+/g, repl)

In addition to the repeated return, the book is missing a colon in the conditional:

return a < b ? -1 (a > b ? 1 : 0);

should be:

return a < b ? -1 : (a > b ? 1 : 0);

Note from the Author or Editor:
Yes, two typos. Replace the line
return return a < b ? -1 (a > b ? 1 : 0);
with
return a < b ? -1 : (a > b ? 1 : 0);

In the pair of examples showing that a var declaration is hoisted but its assignment is not, a named function expression rather than a normal function expression appears. In addition, the name "foo" appears twice, both as the name of the var and the name of the function. The example should perhaps be this instead:
var foo = function () { ... }; // (split over multiple lines as desired)

Note from the Author or Editor:
Yes, I agree that that would be better. Thus: in the last two code snippets before Sect. "The Name of a Function", replace

foo = function foo() {

WITH

foo = function () {

> y; // This results in listed error (ReferenceError: y is not defined)
> y = 4; // This defines and initializes global variable y - no error thrown

Note from the Author or Editor:
True. I was thinking about strict mode. Fix: Replace all of the existing 4 lines with the following 5 lines.

[role="repl"]
------------------------------------
> var x;
> x
undefined
> y
ReferenceError: y is not defined
------------------------------------

Example is shown:

> {} === {} // two different empty objects
false

but this returns a syntax error.

Note from the Author or Editor:
Same issue as on page 10: Not a syntax error in all command lines (e.g. not in Node.js). But a good idea to add parentheses, as shown in the following line:

> ({} === {}) // two different empty objects

Example is shown:

> {} === {} // two different empty objects
false

but this returns a syntax error.

Note from the Author or Editor:
Not a syntax error in all command lines (e.g. not in Node.js). But a good idea to add parentheses, as shown in the following line:

> ({} === {}) // two different empty objects