User Guide

226 Chapter 5: ActionScript Core Language Elements
var
Availability
Flash Player 5.
Usage
var variableName [= value1] [...,variableNameN [=valueN]]
Parameters
variableName
An identifier.
value The value assigned to the variable.
Returns
Nothing.
Description
Statement; used to declare local variables.
If you declare variables inside a function, the variables are local. They are defined for the function
and expire at the end of the function call. More specifically, a variable defined using
var is local to
the code block containing it. Code blocks are demarcated by curly braces ({}).
You cannot declare a variable scoped to another object as a local variable (for more information,
see “Scoping and declaring variables” on page 28):
my_array.length = 25; // ok
var my_array.length = 25; // syntax error
When you use var, you can strictly type the variable. For more information, see “Strict data
typing” on page 24.
Note: You must also use var when declaring properties inside class definitions in external scripts.
Class files also support public, private, and static variable scopes. See “Creating Custom Classes with
ActionScript 2.0” on page 45, and see private
, public, and static.
Example
The following ActionScript creates a new array of product names. Array.push adds an element
onto the end of the array. If you want to use strict typing, it is essential that you use the
var
keyword. Without
var before product_array, you get errors when you try to use strict typing.
var product_array:Array = new Array("MX 2004", "Studio", "Dreamweaver",
"Flash", "ColdFusion", "Contribute", "Breeze");
product_array.push("Flex");
trace(product_array);
// output: MX 2004,Studio,Dreamweaver,Flash,ColdFusion,Contribute,Breeze,Flex
CHAPTER 5
ActionScript Core Language Elements