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ActionScript 3 for Flash, Flex, and AIR
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Essential ActionScript 3.0 (Essential)Essential ActionScript 3.0 (Essential) by Colin Moock
Buy new: $34.64 / Used from: $20.98
Colin Moock wrote the definitive reference for ActionScript 2.0. This book is a complete rewrite and definitely essential.
ActionScript 3.0 Cookbook: Solutions for Flash Platform and Flex Application DevelopersActionScript 3.0 Cookbook: Solutions for Flash Platform and Flex Application Developers by Joey Lott
Buy new: $26.39 / Used from: $10.75
The author covers most of the things you'll want to do with ActionScript 3 in no-nonsense form, with code examples for everything.
Foundation Actionscript 3.0 Animation: Making Things Move!Foundation Actionscript 3.0 Animation: Making Things Move! by Keith Peters
Buy new: $26.39 / Used from: $20.00
A surprisingly good guide to procedural animation in Flash or Flex.
Advanced ActionScript 3 with Design PatternsAdvanced ActionScript 3 with Design Patterns by Joey Lott
Buy new: $31.49 / Used from: $28.98
If you're working on larger projects or a bunch of them you'll benefit from using and reusing these ActionScript design patterns.
ActionScript 3.0 Design Patterns: Object Oriented Programming Techniques (Adobe Developer Library)ActionScript 3.0 Design Patterns: Object Oriented Programming Techniques (Adobe Developer Library) by William Sanders
Buy new: $39.14 / Used from: $9.99
Another useful Design Patterns book for ActionScript 3.0.
Programming Flex 2: The Comprehensive Guide to Creating Rich Internet Applications with Adobe FlexProgramming Flex 2: The Comprehensive Guide to Creating Rich Internet Applications with Adobe Flex by Chafic Kazoun
Buy new: $37.11 / Used from: $0.58
You can write Flex 2 programs without using much ActionScript, but the more you know the more powerful your programs will be. This book is a great starting point for Flex 2.
The Essential Guide to Flex 2 with ActionScript 3.0 (Essentials)The Essential Guide to Flex 2 with ActionScript 3.0 (Essentials) by Charles E Brown
Buy new: $36.49 / Used from: $1.65
Another good Flex 2 resource.
Professional Adobe Flex 2 (Programmer to Programmer)Professional Adobe Flex 2 (Programmer to Programmer) by Rich Tretola
Buy new: $34.12 / Used from: $0.33
A comprehensive guide to Flex 2 with lots of ActionScript 3 samples.
Apollo for Adobe Flex Developers Pocket GuideApollo for Adobe Flex Developers Pocket Guide by Mike Chambers
Buy new: $0.90 / Used from: $0.01
Apollo is now AIR, and this book was written for a prior release of the product. However most of it still applies. Plus I helped write it. Look for it online too.
Object-Oriented ActionScript 3.0Object-Oriented ActionScript 3.0 by Todd Yard
Buy new: $33.64 / Used from: $22.29
The ActionScript 2 version of this book was very handy, so I'm sure the ActionScript 3 version will be well worth your while. If you're new to object-oriented programming this is a good starting point.
ActionScript 3.0 Game Programming UniversityActionScript 3.0 Game Programming University by Gary Rosenzweig
Buy new: $31.49 / Used from: $28.34
I haven't read this yet, but it looks interesting. I always like to promote game programming in Flash and Flex.
Foundation ActionScript 3.0 with Flash CS3 and FlexFoundation ActionScript 3.0 with Flash CS3 and Flex by Todd Yard
Buy new: $26.39 / Used from: $15.41
The first books focusing on ActionScript 3 with Flash CS3 are just coming out. This looks like a good one to try.
ActionScript 3.0 for Adobe Flash CS3 Professional Hands-On TrainingActionScript 3.0 for Adobe Flash CS3 Professional Hands-On Training by Todd Perkins
Buy new: $34.64 / Used from: $14.51
Another good Flash CS3 and ActionScript 3 resource.