Author: Douglas Crockford
Publisher: Yahoo Press, 2008
Pages: 176
ISBN: 978-0596517748
Aimed at: Javascript developers doing more than scripts
Rating: 4.5
Pros: A fresh and insightful account of high-level Javascript
Cons: There's lots more to say
Reviewed by: Ian Elliot

If you think that this book is getting a little long in the tooth - think again. It may only be 176 pages long and it may have been published in 2008, which is a long time ago for a book on any computer topic but it is still essential reading.

The author, Douglas Crockford has been writing about aspects of Javascript for a while and this book is his distilled wisdom. The book has also given rise to some follow on titles with "The good parts" as a subtitle. Don't be fooled. You have to evaluate each one on its merits because the idea of a book on "the good parts" is really only a natural for a langauge like Javascript and with an author who knows the deeper ideas locked up in a topic.

In this case you can rest assured that it is a classic. This is not a book for the Javascript beginner - it's an eye opener for Javascript programmers who think that the language is obvious or not very sophisticated. Javascript is in fact revealed to be a dynamic language with a unique approach to many conventional things such as objects and functions.

The book has ten short chapters:

• Syntax
• Objects
• Functions
• Inheritance
• Arrays
• Regular expressions
• Methods
• Style
• Beautiful features

and each one is worth reading.

The key idea explained in the book is Javascript's approach to objects which is quite different to other languages. If you are writing Javascript as if it really was just a scripting language then you probably won't be using its object-oriented features and you won't need this book. If you see Javascript as playing a key role in your web app then this book shows you how to use it in sophisticated ways that will make your app better in all ways.

You won't get anything much from the book if you are simply interested in getting a few web page scripts to work correctly across browsers. This is about Javascript as an application building language on a par with C# or full Java. From the point of view of someone just trying to make a script work this appears to be academic nonsense. It isn't.

About the only problem with the book is that occasionally it fails to explain the principle well enough in isolation. You have to read the example, try and understand it and then re-read the explanation to see what it means. It also doesn't cover lots of practical aspects of using Javascript - compression, efficiency in general, Ajax, the DOM and so on and there are few hints-and-tips level topics. In fact there are lots and lots of topics not covered by such a slim volume - think of this as the high-level theory of Javascript.

The book also highlights the lack of a really good and complete account of the language that treats it logically and in its own style rather than trying to make it look like classical object-oriented languages. This books contains some of the material that is needed but it runs out of steam far too soon.

This is one of the books you have to read if you hope to be a Javascript expert.

Highly recommended.