Types of Statements
Statement Syntax
The ActionScript Statements
Statements Versus Actions
Onward!
To make something happen in Flash -- whether stopping a sound, playing a movie, running a function, or looping some code -- we use a statement. In fact, an ActionScript program can be defined as nothing more than a list of statements that tell the interpreter what we want Flash to do. Here, for example, is an entire ActionScript program, which consists of four statements and tells the interpreter to load a web page into the browser:
var protocol = "http"; // Statement 1 var domain = "www.moock.org"; // Statement 2 var path = "webdesign/flash/"; // Statement 3 getURL(protocol + "://" + domain + "/" + path); // Statement 4
Scripting a movie with ActionScript is simply a matter of attaching statements to frames, movie clips, and buttons. This chapter explores the syntactic makeup of statements and lists the general statement categories. We'll touch on all the ActionScript statements in this chapter, but some of the more important ones will be examined in detail in later chapters.
Conceptually speaking, there are five core types of statements:
loops
conditionals
ifFrameLoaded
var
set
function
function call
call
return
with
for . . . in
any expression (especially expressions with side effects)
These informal categories help us to understand what we can tell the interpreter to do using statements. At first glance, the list may seem fairly limited. However, we'll see that there are many variations of conditionals and loops and that there are thousands of things we can do via function calls. First, let's see how statements are formed.
Copyright © 2002 O'Reilly & Associates. All rights reserved.