Last month I finished reading the short but densely packed JavaScript book JavaScript: The Good Parts.I had been looking for a book that would cover some of the pitfalls of the language more thoroughly than what I’d read about previously and when I saw this in the bookstore it seemed to fit the bill.

The thesis of the book is that JavaScript is a misunderstood language. It recognizes that there are bad parts to the language, but it contends that once you get past them there are some pretty nice good parts – and that by using only the good parts and avoiding the bad parts, you can write some really great code.

The book covers objects, functions, arrays, regular expressions, closure, and how inheritance works in JavaScript. The last one is probably the most important, since most people are only familiar with classical inheritance, and JavaScript’s prototypal inheritance, although wrapped in a syntax that makes it look classical, is very different. The book also discusses JavaScript’s bad parts and why you should avoid them.

Most of the concepts in the book are well explained, though I did find myself needing to re-read certain sections twice to completely understand the topic. This is in part because the book is very short, coming in at 153 pages (including the index). This is a double edged sword in that it allows you to take in a lot of material in a short amount of time, but sometimes you’re left wishing that a little more time was spent on a certain topic.

One other possible fault with the book (depending on how you look at things) is that it does not cover the DOM at all. The DOM isn’t part of the JavaScript language, but almost everyone who uses JavaScript will need to interact with the DOM. Therefore, this book is really more of a companion piece than a definitive reference for JavaScript programming.

Overall I really liked this book. It gives good coverage to some important topics regarding objects and functions, and gives a good explanation of prototypal inheritance. A lot of language quarks are also pointed out and explained. For example, one thing I didn’t realize was that the arguments array that is implicitly passed to functions isn’t a real array. It’s just an object with a length property. The appendix sections covering the “bad parts” and “awful parts” were also pretty interesting, though I disagree with the author that ++ and — are bad.

Anyway, I highly recommend the book if you’re into JavaScript programming. It’s a nice easy read that covers a lot of ground. Also, this is a non-solicited review, though the link above is an amazon referral link.

If you’re interested, the book’s author gave a one hour talk on this book that touches on a lot of its ideas. You can watch it here (actual talk starts at 2 minutes 15 seconds):