Beginning with the first example, the book is filled with errors (function `hello()' is called without being defined in example 1-1). Some (not all) are enumerated on the book's errata page. Since the first half of the book discusses syntax, a CS background can allow a reader to read around the errors. The second half discusses BOM, DOM, and Ajax making it's impossible to spot the errors without being a JavaScript expert, which makes the book worthless.

The last third of the book is written as a first person narrative. The book should be about JavaScript, not the author.

Bad writing takes place everyday. How a book like this made it past the editors at a reputable publisher like O'Reilly makes one wonder about their process.

Avoid this book.

Really hard reading, goes all over subject matter in first chapters, assumes reader has already read much better book on subject. If you are new to JavaScript skip this book. It will make you hate Learning JavaScript which I suggest the title be changed to, "Learning to Hate JavaScript". I will watch out for author and never buy a book by her again.

I've been learning JavaScript off and on, with some success, for three months. In doing so, I've skimmed about a half-dozen books and tried the following three, so far, "graded" below:

Learning JavaScript (Powers B-)
VQS JavaScript and Ajax (Negrino & Smith C+)
O'Reilly JavaScript Pocket Reference (Flanagan B)

Very good first draft. Powers either over-powered her editor (my guess) or perhaps they couldn't find an editor technically aware enough for this particular task. Hence, it's full of typos, "meant to says," and interesting logic puzzles to teach something that an outsider would have told her she needs to define clearly first with a simple example. Despite this, Powers clearly knows her stuff, has a love for the subject matter and goes farther than many other authors to convey concepts and vocabulary to teach and mentally structure the material. Like most JavaScript authors she rarely lowers herself to actually explain how web-page items and forms pass JavaScript function calls and data to JavaScript in the first place (so what's the point?). Despite the ill-considered examples of the concepts she's trying to convey, she has a good instinct for keeping the writing succinct and she won't waste your time. If you don't understand something, it'll be clear which part you need to restudy. Topics are well indicated by well-chosen headers. Despite the hurried editing, and occasionally self-centered style, this book has the gift of being up-to-date and conscious of changes in the field. This book won't be enough by itself and you'll have to hunt the web heavily to find complete examples showing how the web-page talks to the JavaScript she's writing about. It's still the best JavaScript book I've found to date. With a well-considered rewrite this could be a great book.

Oh, yeah ... she really wants you to know she prefers a Mac over a PC.

I am an experienced software engineer who has worked in many languages and is trying to get up to speed with JavaScript(JS). I am a novice when it comes to JS but I have used it in a commercial environment before.

I have returned this book since the number of errors in the examples and question sections are far too many. These sections are the important part of the book that one learns from. I got halfway through Chapter 3 and gave up since almost half of all the examples are incorrect. For example an alert("some string") call was listed with three different strings in the example, a reference to it in the text and the expected outcome.

Also for anyone who is not a developer or has little knowledge of common terms in development this book is NOT for you. Shelly assumes you know what a strongly/loosely typed language is and other such concepts.

As a n00b to web development, this book was not appropriate for me, and in retrospect, I realize I must not have been the intended audience. As a person who has taught and practiced technical writing and composition in the past, I would say that this book was intended for someone who was already familiar with other scripting languages and was looking for a quick entrance into Javascript. For my part, I was hoping for more explanation of the basic mechanics of Javascript and the DOM than this text offers. I haven't gotten past the initial chapter on defining variables and DOM, as both chapters used unfamiliar technical terms and concepts without explaining them. Why have an introductory chapter on DOM without explaining, step-by-step, what the explanatory terms mean? In other words, each concept could and should be further disaggregated and explained. This is NOT a book for the beginner!!

However, beginners take heart! I'm happy to report that I have found a truly helpful line of books with which to compare this book (and the O'Reily line of books, in general). After purchasing and reading through a couple of books from this aforementioned line (including one on CSS and XHTML), which ARE suited for the beginner, I can say with confidence that a beginner's book can be written and is available. I won't name the line (as I don't intend for this review to be an advertisement), but I will say that it is associated with a popular on-line development website and forum, and one can find it by looking around the developer forums. (One can even download free chapters of these books for personal review!!) If the books give you hangups -- which I doubt -- then one can easily go to the forum (which is quite hospitable to n00bs!!) and tune in to some truly "open-source" learning. Ask an intelligent, thoughtful question and the forum will respond.

As far as _Learning Javascript_, I would say that perhaps someone already initiated into the developer scene could benefit from this book. But, then, why bother when more comprehensive references are available? For my part, I'll reread the book when I have a basic working knowledge of Javascript and see what I can pick up. After all, I do own it, now. It will make an alright back-up reference. Best wishes, fellow n00bs!!