Editing ActionScript (section)

===Timeline by ActionScript version===
====2000–2004: ActionScript "1.0" ====
With the release of Flash 5 in September 2000, the "actions" from Flash 4 were enhanced once more and named "ActionScript" for the first time.<ref>{{Cite web|url=https://helpx.adobe.com/x-productkb/multi/release-notes-flash-player-11.html|title=Flash Player 11, AIR 3 Release Notes|website=helpx.adobe.com|access-date=2016-10-07}}</ref> This was the first version of ActionScript with influences from [[JavaScript]] and the [[ECMA-262]] (Third Edition) standard, supporting the said standard's object model and many of its core [[data type]]s. Local variables may be declared with the {{Mono|var}} statement, and user-defined [[function (computer science)|functions]] with [[parameter (computer science)|parameter]] passing and [[return statement|return]] values can also be created. Notably, ActionScript could now also be typed with a text editor rather than being assembled by choosing actions from drop-down lists and dialog box controls. With the next release of its authoring tool, Flash MX, and its corresponding player, [[Adobe Flash Player|Flash Player 6]], the language remained essentially unchanged; there were only minor changes, such as the addition of the {{Mono|switch}} statement and the "strict equality" ({{Mono|1====}}) operator, which brought it closer to being [[ECMA-262]]-compliant. Two important features of ActionScript that distinguish it from later versions are its loose type system and its reliance on prototype-based [[inheritance (object-oriented programming)|inheritance]]. Loose typing refers to the ability of a [[variable (programming)|variable]] to hold any type of data. This allows for rapid script development and is particularly well-suited for small-scale scripting projects. Prototype-based inheritance is the ActionScript 1.0 mechanism for code reuse and object-oriented programming. Instead of a {{Mono|class}} keyword that defines common characteristics of a [[class (computer science)|class]], ActionScript 1.0 uses a special object that serves as a "prototype" for a class of objects. All common characteristics of a class are defined in the class's prototype object and every [[Instantiation (computer science)|instance]] of that class contains a link to that prototype object.

====2003–2006: ActionScript 2.0 ====
The next major revision of the language, ActionScript 2.0, was introduced in September 2003 with the release of Flash MX 2004 and its corresponding player, [[Adobe Flash Player|Flash Player 7]]. In response to user demand for a language better equipped for larger and more complex applications, ActionScript 2.0 featured compile-time [[type checking]] and class-based [[syntax of programming languages|syntax]], such as the keywords {{Mono|class}} and {{Mono|extends}}. While this allowed for a more structured object-oriented programming approach, the code would still be compiled to ActionScript 1.0 [[bytecode]], allowing it to be used on the preceding Flash Player 6 as well. In other words, the [[Class-based programming|class-based]] inheritance syntax was a layer on top of the existing prototype-based system. With ActionScript 2.0, developers could constrain [[variable (programming)|variables]] to a specific type by adding a type annotation so that type mismatch errors could be found at [[compile-time]]. ActionScript 2.0 also introduced class-based inheritance syntax so that developers could create classes and interfaces, much as they would in class-based languages such as [[Java (programming language)|Java]] and [[C++]]. This version conformed partially to the [[ECMAScript]] Fourth Edition draft specification.

====2006–2020: ActionScript 3.0====
In June 2006, ActionScript 3.0 debuted with [[Adobe Flex|Adobe Flex 2.0]] and its corresponding player, [[Adobe Flash Player|Flash Player 9]]. ActionScript 3.0 was a fundamental restructuring of the language, so much so that it uses an entirely different [[virtual machine]]. Flash Player 9 contains two virtual machines, AVM1 for code written in ActionScript 1.0 and 2.0, and AVM2 for content written in ActionScript 3.0. ActionScript 3.0 added limited support for [[hardware acceleration]] ([[DirectX]], [[OpenGL]]).

The update to the language introduced several new features:
* [[Compile-time]] and [[Run time (program lifecycle phase)|run-time]] type checking—type information exists at both compile-time and runtime.
* Improved performance from a class-based inheritance system separate from the prototype-based inheritance system.
* Support for [[Java package|packages]], [[namespace]]s, and [[regular expressions]].
* Compiles to an entirely new type of [[bytecode]], incompatible with ActionScript 1.0 and 2.0 bytecode.
* Revised Flash Player [[API]], organized into [[Java package|packages]].
* Unified [[event handling]] system based on the [[DOM Events|DOM event handling]] standard.
* Integration of [[ECMAScript for XML]] (E4X) for purposes of [[XML]] processing.
* Direct access to the Flash [[run-time system|runtime]] display list for complete control of what gets displayed at runtime.
* Completely conforming implementation of the [[ECMAScript]] fourth edition draft specification.
* Limited support for dynamic 3D objects. (X, Y, Z rotation, and texture mapping)