ActionScript: The Definitive Guide

Further ActionScript Concepts

You’ve already been introduced to many of the fundamental elements that make up ActionScript: data, variables, operators, statements, functions, and arguments. Before we delve deeper into those topics, let’s sketch out the rest of ActionScript’s core features.

Flash Programs

To most computer users, a program is synonymous with an application, such as Adobe Photoshop or Macromedia Dreamweaver. Obviously, that’s not what we’re building when we program in Flash. Programmers, on the other hand, define a program as a collection of code (a “series of statements”), but that’s only part of what we’re building.

A Flash movie is more than a series of lines of code. Code in Flash is intermingled with Flash movie elements, like frames and buttons. We attach our code to those elements so that it can interact with them.

In the end, there really isn’t such a thing as a Flash “program” in the classic sense of the term. Instead of complete programs written in ActionScript, we have scripts : code segments that give programmatic behavior to our movie, just as JavaScript scripts give programmatic behavior to HTML documents. The real product we’re building is not a program but a complete movie (including its code, timelines, visuals, sound, and other assets).

Our scripts include most of what you’d see in traditional programs without the operating-system-level stuff you would write in languages like C++ or Java to place graphics on the screen or cue sounds. We’re spared the ...