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<h1>Errata<div style="font-size: 70%"><a class="subtlelink" href="index.html">Eloquent JavaScript</a>, 3rd Edition</div></h2>

<p>These are the known mistakes in the <strong>third edition</strong>

of the book. For errata in the first edition,

see <a href="https://eloquentjavascript.net/1st_edition/errata.html">this

page</a>. For the second edition,

see <a href="https://eloquentjavascript.net/2nd_edition/errata.html">this

page</a>. To report a problem that is not listed

here, <a href="mailto:marijnh@gmail.com">send me an email</a>.</p>

<p>Issues whose page number is followed by an ordinal number are only

present up to the print denoted by that number. I.e. those followed by

“1st” were fixed in the second print.</p>

<h2>Chapter 2</h2>

<p><strong>Page 34</strong> (1st) <em>Updating Bindings Succintly</em>: Where it

says <code>counter-</code> it should be <code>counter--</code>.</p>

<h2>Chapter 5</h2>

<p><strong>Page 91</strong> (3rd) <em>Composability</em>: Due to an initial

mistake in the script data set, the results of the computations on

this page differ from the ones with the current, corrected data. The

average year for living scripts should be 1165, the average for

non-living scripts should be 204.</p>

<h2>Chapter 6</h2>

<p><strong>Page 111</strong> (2nd) <em>Inheritance</em>: In the second

paragraph below the example code, instead of “<code>content</code>

method”, the text should say “<code>element</code> function”.

<h2>Chapter 8</h2>

<p><strong>Page 134</strong> (2nd) <em>Error Propagation</em>: In the third

paragraph of the section, a function <code>promptInteger</code> is

referred to. The function is actually

called <code>promptNumber</code>, and the word “whole” should be

dropped from the sentence (it accepts non-whole numbers, too).</p>

<h2>Chapter 10</h2>

<p><strong>Page 168</strong> (1st) <em>Modules as Building Blocks</em>: In “each

needs it own private scope“, it should say “<em>its</em> own private

scope“.</p>

<h2>Chapter 11</h2>

<p><strong>Page 189/190</strong> (4th) <em>Networks are Hard</em>: The text

under the code that defines <code>request</code> claims the function

will give up after four attempts and a second. In fact, it gives up

after three attempts, in three-quarter second.</p>

<h2>Chapter 14</h2>

<p><strong>Page 231</strong> (5th) <em>Moving Through the Tree</em>: Below

the code example, the text claims

that <code>for</code>/<code>of</code> loops don't work on DOM child

lists. But in current (even as of the book's release) browsers they

do.</p>

<p><strong>Page 234</strong> (2nd) <em>Creating Nodes</em>: In the

code, “edition” is misspelled as “editon”.</p>

<h2>Chapter 15</h2>

<p><strong>Page 255</strong> (7th) <em>Mouse Motion</em>: The second

paragraph on the page claims that you can isolate a button from

the <code>buttons</code> bitmask with the remainder operator, but that

doesn't really work (you'd also need a division and a floor, which

gets too obscure to go into in this chapter).</p>

<p><strong>Page 258</strong> (3rd) <em>Load Event</em>: The description of

the <code>beforeunload</code> claims that you just need to return a

string from your event handler. For handlers registered

with <code>addEventListener</code> you, in fact, need to

call <code>preventDefault</code> and set a <code>returnValue</code>

property to get the warn-on-leave behavior.</p>

<h2>Chapter 16</h2>

<p><strong>Page 271</strong> (8th) <em>Actors</em>: Near the bottom of the

page, the book incorrectly uses the term <em>phase</em> (of a sinus

wave) where it should say <em>period</em>.</p>

<p><strong>Page 278</strong> (8th) <em>Motion and Collision</em>: The code

that defines the <code>touches</code> method unintentionally (though

harmlessly) used <code>var</code> instead of <code>let</code> to

define variables.</p>

<p><strong>Page 285</strong> (2nd) <em>Pausing the Game</em>: The text

refers to the <code>arrow</code> binding, where it should

say <code>arrowKeys</code>.</p>

<h2>Chapter 19</h2>

<p><strong>Page 336</strong> (5th) <em>The State</em>: The text mentions the

property <code>fillColor</code> where it should

say <code>fillStyle</code> instead.

<h2>Chapter 20</h2>

<p><strong>Page 367</strong> <em>A File Server</em>: The part that

talks about “the output stream to the request” should say “the stream

from the request” instead.</p>

<p><strong>Page 369</strong> (1st) <em>Directory

Creation</em>: <code>MKCOL</code> stands for “make collection”, not “make

column” as the book claims.</p>

<h2>Chapter 21</h2>

<p><strong>Page 373</strong> (3rd) <em>HTTP Interface</em>: There is a

superfluous closing brace at the end of the example JSON snippet.</p>

<h2>Exercise Hints</h2>

<p><strong>Page 414</strong> (3rd) <em>A Modular Robot</em>:

The <code>dijkstrajs</code> package name is misspelled

as <code>dijkstajs</code>.