The subject matter is expertly covered and unless you were aware of the changes in jQuery 1.3, compared to the older version that the original was focused it would be difficult to tell which portions of the book are new – the revision and updates to the original are seamless.
Quite rightly, Swedberg and Chaffer do not explain all differences between jQuery 1.3 and its predecessors – they rightly assume that if you’re reading “Learning JQuery 1.3″ then you don’t need to be informed of exactly how jQuery 1.3 differs from the version they previous covered. The book flows better because of this and remains very easy to understand because of this approach.
There is no hint of the selector engine in 1.3 being any different than what was already covered. The language used for explaining the different concepts to the reader is more precise, especially so in the Events chapter and this makes understanding the concepts being covered much more easy – for this reason alone buying the revised edition is well worth the money.
The book doesn’t focus on new additions that were freshly added to jQuery 1.3 but also ones that had been added to jQuery since the first edition was published; JSONP, which was introduced in jQuery 1.2 is covered in the chapter on AJAX, as is the more low-level $.ajax() method; it also mentions which features have been removed from jQuery since the first edition was published – XPath being one such example. The listing of development tools has also been reworked, as has the Online Resources section. These listings mention resources that are current and up-to-date.
I remember mentioning in my review of the first book (trying hard not to use the word ‘original’ again!) that until a later edition of it was released that you wouldn’t be able to find a better book on the subject. I stand by that assertion – the only book that covers jQuery better than the first edition of “Learning jQuery” is the second edition of the same.