What else is new in the 5th edition?
1. Nested functions and closures.
3. A new chapter on Modules and Namespaces.
5. Coverage of the legacy (Level 0) DOM has been combined with the W3C standard DOM. More consolidation. Less flipping back and forth.
6. Cookies and Client-Side Persistence. Updated coverage on cookies, and brand new coverage of other client-side persistence techniques, like IE userData persistence, and Flash Shared Object Persistence.
7. AJAX - Coverage of scripted HTTP calls using the now famous XMLHttpRequest object.
8. XML - Demonstrates how to create, load, transform, query, serialize, and extract info from XML docs.
10. Scripting Java Apps and Flash Movies - Another brand new chapter.
So, is the 5th edition worth the purchase? Absolutely. This book is a must-have for any web development library. I turn to it repeatedly. Here's an example.
"Really?!", he asked, astonished. I opened "The Definitive Guide" to the part on cross-frame scripting and bookmarked it for them.
"Oh, wow! GREAT!", he exclaimed, "That completely solves our problem. Totally cool!" and zipped away book in hand. Hours later, they had it worked out, rather than days with the server-side solution.
Great job, again, David! If you develop websites in any capacity, you need this book. It should be on every developer's shelf.