User Guide

32 Using ActionScript to Create Components
Defining methods
Methods define the operations that your class can perform. You define methods in the body of
the class. Your methods can override a method of a superclass, or define new functionality for
your components.
If the method adds new functionality, you define it using the
function keyword, as the
following example shows:
public function myMethod():void {
// Method definition
}
If you define this method as a public method, users of the class can call it.
You can also define private methods, as the following example shows:
private function internalMethod():void {
// Method definition
}
Private methods are for internal use by the class, and cannot be called by users of the class.
If the method overrides a method in a superclass, you must include the
override keyword
and the signature of the method must exactly match that of the superclass method, as the
following example shows:
override protected function createChildren():void {
// Method definition
}
Your methods may take required or optional arguments. To make any of the arguments
optional, assign default values to them, as the following example shows:
override public validate(value:Object = null,
supressEvents:Boolean = false):ValidationResultEvent {
// Method definition
}
If the method takes a variable number of arguments, use the “...” syntax, as the following
example shows:
function foo(n:Number, ... rest):void {
// Method definition
}
NOTE
If a function takes no arguments, ensure that you specify its argument list as empty
parentheses (), not as (void). The latter specifies a single argument of type Object named
void.
If a function, other than a constructor, returns no value, you must specify a return value of
void. If you omit the return type, the compiler issues a warning.