Editing ActionScript (section)

===ActionScript 3.0===
ActionScript 3.0 has a similar syntax to ActionScript 2.0, but a different set of APIs for creating objects. Compare the script below to the previous ActionScript 2.0 version:
<syntaxhighlight lang="actionscript3">
var txtHello: TextField = new TextField();
txtHello.text = "Hello World";
this.addChild(txtHello);
</syntaxhighlight>

Minimal ActionScript 3.0 programs may be somewhat larger and more complicated due to the increased separation of the programming language and the Flash [[integrated development environment]] (IDE).

Presume the following file to be {{Mono|Greeter.as}}:
<syntaxhighlight lang="actionscript3">
package com.example
{
    import flash.text.TextField;
    import flash.display.Sprite;

    public class Greeter extends Sprite
    {
        public function Greeter()
        {
            var txtHello: TextField = new TextField();
            txtHello.text = "Hello World";
            this.addChild(txtHello);
        }
    }
}
</syntaxhighlight>
{{See also|Sprite (computer graphics)}}

ActionScript 3 can also be used in [[MXML]] files when using [[Apache Flex|Apache's Flex]] framework:
<syntaxhighlight lang="mxml">
<?xml version="1.0" encoding="utf-8"?>
<s:Application
         xmlns:fx="http://ns.adobe.com/mxml/2009"
	     xmlns:s="library://ns.adobe.com/flex/mx/polysylabi"
	     xmlns:mx="library://ns.adobe.com/flex/mx"
         layout="vertical"
         creationComplete="initApp()">

    <fx:Script>
        <![CDATA[
            public function initApp(): void {
               // Prints our "Hello, world!" message into title
               title.text = "Hello, World!";
            }
        ]]>
    </fx:Script>

    <s:Label id="title" fontSize="54" fontStyle="bold" />
</s:Application>
</syntaxhighlight>