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 6: Statements

In Flash 4, set was called Set Variable, and it was often used to dynamically assign

variables that had programmatically generated sequential names. It allowed pro-

grammers to simulate arrays, which were not a native part of Flash 4 ActionScript.

Since arrays were added in Flash 5, set is rarely used anymore. In most cases, a vari-

able can be referenced dynamically with the object property access operator,

[]. For

example,

// Set the value of firstName in the form_mc movie clip.

form_mc["first" + "Name"] = "jane";

// Set the value of firstName in the current movie clip.

this["first" + "Name"] = "jane";

However, set is required when dynamically referring to a local variable in a function

(because local variables are not properties of any exposed ActionScript object).

The function Statement

Just as the var statement is used to declare (i.e., create) variables, the function state-

ment is used to declare functions. The function statement has the following syntax:

function funcName (param1, param2, param3,...paramn) {

statements

}

The keyword function begins the statement; funcName is the name of the function

being declared;

param1 through paramn define the parameters required by the func-

tion when it executes (parameters are separated by commas);

statements is a list ...