When it comes to layout and ease of reading, I can't really put a finger on anything. In the very beginning of the book, various typographic conventions and such used throughout the book are explained but there shouldn't be room for much misunderstanding even if you skip that part. The pages read easily and have a nice balance of text and whitespace. Code examples, of which there are plenty although usually very short, are all clear, concise and easily identified.

The book takes a rather hands-on approach to learning and you're encouraged to try out short code examples as you read them. It works nicely, I think, at least if you're using Firebug (which the author suggests you do and also instructs you how to set up) since the book shows you both what you should type as well as the expected response from the Firebug console.

JavaScript basics

The book is more or less divided in two parts, with the first part (consisting of the first 4 chapters) dealing with general, basic JavaScript programming and the second part taking on the object-oriented aspects as well as dealing with the browser environment and discussing some design patterns.

And the first chapters do really start with the very basics. After a short introduction to the language in chapter 1, including its history as well as how it fits in among other languages, you're taken through the basic syntax of the language, the available operators and the primitive data types. It then naturally progresses to discuss functions and objects, including scope, the important topic of closures and how everything in JavaScript is an object.

Prototypes, the browser and patterns

Now, part 2 is where it gets more interesting. Chapters 5 and 6 explain in great detail how JavaScript is a prototypical language and shows with many examples how to write object-oriented JavaScript using constructor functions and prototype chaining. It's my understanding that many people new to JavaScript have problems grasping this part and the two chapters seem appropriately thorough with many examples and even a few diagrams when necessary.

I won't say much about chapter 7. It simply walks you through the objects and functions available when running JavaScript in the browser, ie. the document and browser object models (DOM and BOM). It's not the most interesting chapter seen in the context of learning the language but for those wanting to use it for developing web sites/apps, it's a nice and quick introduction if you don't have a book dedicated to that.

Chapter 8 finishes the "meat" of the book with a discussion of various common coding and design patterns, ranging from namespacing to JSON and singletons. They are all good topics but some of them get so little space that they seem more like appetizers for further study than anything else. That said, it's a good chapter and highlights how the language features you've just learned can and are being used to build real applications.

Near the end you'll find a few obligatory appendices listing things like reserved words, built-in objects and regular expressions. They are nice and detailed and about what you'd expect from a book like this, nothing more, nothing less.

A few comments

As mentioned earlier, it's suggested that you use Firebug while reading the book, but I suppose any JavaScript console could work and it's only meant as a tool to give you instant feedback. For the most part, the book deals with JavaScript in a strict language-only way, ie. it doesn't care if you're using JavaScript in the browser, on the server or in more exotic places. In fact, I was a bit surprised to see that, given this environment-agnostic approach, the author still chose to devote all of chapter 7 to the browser environment (DOM, BOM, etc). Not that it's bad or useless information (and it's certainly a good start), but you might want to look at other books for a more thorough introduction to client-side web development.

On the other hand, there are some areas that perhaps could've used some more space. Eg. things like public/privileged/private methods and properties in the context of JavaScript objects are only mentioned briefly in chapter 8 and a few of the other patterns discussed there could easily be "upgraded" and given a few more paragraphs.

You also won't find much about the newest editions of JavaScript, perhaps due to the book being, after all, somewhat tied to the browser environment where the newest versions are far from ubiquitous. As such, the book doesn't deal with the features introduced in JavaScript 1.6 and newer.

I'd say the ideal reader for this book is one with at least a bit of programming experience. While the first chapters are very basic (more experienced programmers might want to just skim these) the later topics do get more advanced and if this is your very first experience with programming, some of it could provide a challenge.

Conclusion

To summarize, I think this is a great book for learning the JavaScript language. It could perhaps have been a bit heavier on the OO side of things and maybe let some of the browser stuff go, but for a good all-round book on modern JavaScript this is a good bet, whether you're looking to taking your JavaScript skills to the next level or adding another language to your resumé. Depending on what you'll be using JavaScript for, you might also want to supplement with some material about all the good stuff in version 1.7 and/or DOM scripting.

If you want to get a taste of the book, there's a sample chapter available here in PDF format. It's chapter 2 which mostly talks about basic stuff like primitive data types, arrays and loops.

Finally, you can get the book here: Amazon.com (or Amazon.co.uk)
- or directly from Packt Publishing.