ActionScript for Flash MX: The Definitive Guide, Second Edition

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Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

Built-in ActionScript Classes and Objects

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Built-in ActionScript Classes and Objects

We’ve really come a long way since Chapter 1. Our first exposure to ActionScript

was a simple perusal of the items in the Actions panel. Since then, we’ve studied data

and expressions, operators, statements, and functions; and now we’ve explored the

concept of classes and objects. It’s time to put the final brush strokes on the picture

we’ve been painting of the ActionScript language.

ActionScript comes with a variety of syntactic tools: expressions contain data; opera-

tors manipulate data; statements give instructions; and functions group instructions

into portable commands. They constitute ActionScript’s grammar, but until now,

our vocabulary has been very limited. The built-in classes and objects of Action-

Script fill that void and give us lots of interesting things to talk about.

Built-in Classes

Just as we define our own classes to describe and manipulate objects created accord-

ing to our specifications, ActionScript defines its own classes of data. A variety of

prefabricated classes, including the Object class, are built right into the ActionScript

language. The built-in classes can control the physical environment of a Flash movie.

For example, one of the built-in classes, the Color class, ...