O'Reilly logo

Introduction to Flex 2 by Roger Braunstein

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

ActionScript 3.0

The common language of Flex 2 applications is ActionScript 3.0. You can't use any older versions of ActionScript, nor is it possible to create a functional application without at least some ActionScript 3.0. Additionally, we will soon see that MXML and AS3 are fundamentally related.

ActionScript's third incarnation is a mature language, as well as being substantially different from ActionScript 2. This chapter will rapidly cover all the fundamental aspects of ActionScript 3.0, but is by no means a full course. For more instruction, there is a list of useful further reading at the bottom of this Short Cut.

Where Are You Coming From?

Readers who understand ActionScript 2 should be comfortable transitioning to ActionScript 3.0. The following chapter specifically addresses new concepts since AS2, so read on!

Readers versed in C# or Java should find themselves at home with AS3 in short time, but should note a few differences in syntax and features. In any case, this chapter assumes, at minimum, basic knowledge of object-oriented programming.

Main Features

ActionScript is an ECMAScript language; ActionScript 3.0 implements the draft of ECMAScript (ECMA-262) Edition 4. This means two things: one, its true name is ridiculous and you don't have to remember it, and two, it is a draft, so there may be incremental changes in the future. Ecma International is an international standards organization that oversees ECMAScript and other technological standards. JavaScript is another implementation ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required