User Guide

308 Chapter 2: ActionScript Language Reference
function
Availability
Flash Player 5.
Usage
function functionname ([parameter0, parameter1,...parameterN]){
statement(s)
}
function ([parameter0, parameter1,...parameterN]){
statement(s)
}
Parameters
functionname
The name of the new function. This parameter is optional.
parameter An identifier that represents a parameter to pass to the function. This parameter is
optional.
statement(s) Any ActionScript instruction you have defined for the body of the function.
Returns
Usage 1: Nothing.
Usage 2: A reference to the anonymous function.
Description
Statement; comprises a set of statements that you define to perform a certain task. You can define
a function in one location and invoke, or call, it from different scripts in a SWF file. When you
define a function, you can also specify parameters for the function. Parameters are placeholders
for values on which the function operates. You can pass different parameters to a function each
time you call it so you can reuse a function in different situations.
Use the
return statement in a function’s statement(s) to cause a function to generate, or return,
a value.
You can use this statement to define a
function with the specified functionname, parameters,
and
statement(s). When a script calls a function, the statements in the function’s definition are
executed. Forward referencing is permitted; within the same script, a function may be declared
after it is called. A function definition replaces any prior definition of the same function. You can
use this syntax wherever a statement is permitted.
You can also use this statement to create an anonymous function and return a reference to it. This
syntax is used in expressions and is particularly useful for installing methods in objects.
For additional functionality, you can use the
arguments object in your function definition.
Some common uses of the
arguments object are creating a function that accepts a variable
number of parameters and creating a recursive anonymous function.
CHAPTER 2
ActionScript Language Reference