Errata for Head First JavaScript

Chapter 1 page 14 Exercise Solution. Description of "value" listed as "the current value of the ZIP field" but the arrow is pointing to this.value in input id="bedrooms" div

The code sample shows an alert, whose content is the value of the myShowSeatStatus() function. alert(myShowSeatStatus(23)); However, the code in that function, (which is a reference to showSeatStatus()), does nothing but generate an alert. So the example generates an alert, the content of which is anoterh alert (generated by the function called within the alert). It would make sense if showSeatStatus() simply assembled the text string to be displayed in the alert, but that's not what it is. It's not part of the codebase for the projects in the book so it's not going to mess up any readers' code, but it is confusing and I don't think it's correct.

in the this.containsText function literal, the return function has one too many open parens

The expression metacharacters all have lines drawn to their correct meanings, but the order of the 2nd and 6th answers have been reversed from the previous page. In other words, you've reversed the order of the sentences "The sub-pattern is optional..." and "The subpattern is required..."

Missing function arguments do not become null. Instead they are undefined.

display:none and display:block are offered as an alternative to visible. But as the buttons are arranged in a single row, display:inline rather than display:block might be more appropriate. Arguably, it would be better to use the display rather than the visibility style for Stick Figure Adventure, as the hidden button should be treated as not existing. Otherwise the remaining (single) button isn't centered exactly.

"The alert messages have reversed the usage of variables i & j - should be like "Seat " + j + " in row " + i + " is available."" Following on to this, if we wish to maintain the format of the previous example of this type from page 208, we should also add one to seat and row number so there is no "Row 0" or "Seat 0". Thus: alert("Seat " + (j+1) + " in row " + (i+1) + " is available.");

If you turn to page 266 in Chapter 6 where there is an exercise solution. There is a part of the code that has been incorrectly crossed out. See below for what is in the text book: Msg += "Global"; // "Local"; (the comment says "The intended text was commented out to keep it out of the message") It appears the wrong part was crossed out. It should have been everything after the // that needs to be crossed out: Msg += "Global"; // "Local"; (like this)

Both alert statements have the "seat" and "row" variables swapped. It appears: alert("Seat "+i+" in row "+j+" is available."); It should be: alert("Seat "+j+" in row "+i+" is available."); Same error is in the "unavailable" alert statement.

there is a semi-colon missing after the curScene = 2 in the middle of the solution code.

there is a semi-colon missing after the curScene = 2 in the middle of the sample code.

there is a semi-colon missing after the curScene = 2 in the middle of the sample code.

When running the example directly from my computer (i.e. opening youcube13.html directly in my browser), the page shows the initial body components and the image wait.gif and never proceeds. I was able to debug this and noticed that within handleRequest, ajaxReq.getStatus() is 0 (zero) rather than the expected 200 (HTTP's OK). I suspect it is due to the difference between the file:/// protocol and the HTTP:// protocol. To get the example to work, change handleRequest()'s first if-statement test to: if (ajaxReq.getReadyState() == 4 && ((ajaxReq.getStatus() == 200) || (ajaxReq.getStatus() == 0))) {

The code in both the problem and solution compare the length of the blog to the variable i. The code would not work since the variable is out of scope at this point, because it was declared as part of the for loop.

I think this line on page 384 of H.F. java script: decisionElem.appendChild("Decision 1 -> Scene 1 : Fork in the road.")); should be: decisionElem.appendChild(document.createTextNode("Decision 1 -> Scene 1 : Fork in the road.")); The line in the book throws a "type mismatch" error.

example shows the property to get the height of the client window to be clientWindowHeight - it should be clientHeight.

the placeOrder function should take in the form object as a parameter in order for the form.submit() to work.... same error as pages 73 and 74

CURRENT: The key to accessing a web page element with JavaScript is the id attribute of the HTML tag. REVISED: The key to accessing a web page element with JavaScript is the id attribute of the input tag.

The sample code on page 73 and 74 won't work because the form in "form.submit()" does not have a form object to work with. I think placeOrder should probably be getting the form object in as a parameter.

In the touchRock function, the operation of getting the userName first is missing. function touchRock() { userName = readCookie("irock_username"); [ Rest of code is correct ] }

Under the second large paragraph with the seat# functions, <img id="seat14" src=" alt="" /> is missing a quotation mark under src=. It should be <img id="seat14" src="" alt="" /> instead.

I'm not sure if you would consider this a mistake. I think that I read in the XHTML Head First that there should probably be a space between the /> and everything preceding it in an empty tag. Like this: <br/> to <br /> just to accommodate older browsers. On page 300-302, the code <input id="phone" name="phone" type="text" size="12" onblur="validateNonEmpty(this);"/> there is no such space.

Perhaps I am misunderstanding this, but on page 309 it says "The purpose of this.form in the Bannerocity code is to gain access to the help text element that is associated with a particular input field. Remember that this.form is a reference...." I understand the concept presented here but I don't see it being used, which confuses me as to why the text above implies that it is being used. If this method comes up in later pages, why not put this question after it comes up in the book? To me, it seems like it might confuse a reader who has never seen this before since it hasn't even been used in the book yet. What is being used is a document.getElementById('help_text_name') instead of a this.form["help_text"].... especially since the book mentions that the form approach is more concise but it doesn't seem to be using it?

You give 2 examples of character classes, one is /d[iu]g/ and the other is /$d[d.]/ . Shouldn't that second example be /$d[.d]/? The difference is between the brackets.

On page 338, the answer key shows the answer is return validateRegEx ( /^[w.-_/+]+@[w_]+(.w{2,4})+$/..... but shouldn't it be validateRegEx (/^[w.-_/+]+@[w_]+[.w{2,4}]+$/..... (using brackets instead of parentheses for testing the domain suffix) ?

font-color should just be color. font-color is not a valid css property.

I think the second code sample should actually be this: decisionElem.appendChild(document.createTextNode("Decision 1 -> Scene 1: Fork in the road.")); it is currently missing the createTextNode portion.

The ceiling function doesn't work in either Firefox or IE. Is it in this version of the standard?

I think that's not correct that 'undefined' and 'not defined' mean exactly the same thing. 'not defined' means, that the variable does not exists/has not been created. 'undefined' means an undefined state, the variable exists/has been created but it's not initialized (no value has been assigned to the variable) example for undefined: <code> var testVariable; alert(testVariable); </code> the result is an alert-box with message-text 'undefined' example for not defined: <code> alert(testVariable); </code> the result is a message in the error console:'testVariable is not defined'