ActionScript for Flash MX: The Definitive Guide, Second Edition

This is the Title of the Book, eMatter Edition

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

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Chapter 1: A Gentle Introduction for Nonprogrammers

objects, our program’s conceptual model is reflected by an intuitive syntax that looks

like this:

room.addBall( );

ball.diameter = 5;

ball.startMoving( );

In general terms, the object (noun) comes first, followed by a dot (.), followed by

either a function (verb) or a variable (adjective). The function does something to the

object, while the variable tells us something about the object. Functions associated

with an object are often called methods. Variables associated with an object are often

called properties. Here are some examples:

object.method();

boy.run( );

someMovieClip.play( );

object.property = value;

boy.speed = 5;

someMovieClip._width = 60;

Object-oriented programming (OOP) is an approach in which objects are the funda-

mental building blocks of a program. There are, however, varying degrees of OOP

depending on the language and the developer’s taste. Purists insist that every part of

a program should be contained by an object (this rule is enforced by the Java pro-

gramming language). Others are happy using objects to structure only certain parts

of a program (this is common in ActionScript).

Regardless, you should become familiar with objects, because they are intrinsic to

ActionScript’s makeup. Nearly everything in Flash—from ...