MACROMEDIA FLASH 8-LEARNING ACTIONSCRIPT 2.0 IN FLASH - Page 204

204 Functions and Methods
class Person {
public static var numPeople:Number = 0;
// instance members
private var _speed:Number;
// constructor
public function Person(speed:Number) {
Person.numPeople++;
this._speed = speed;
}
// static methods
public static function getPeople():Number {
return Person.numPeople;
}
// instance methods
public function walk(speed:Number):Void {
this._speed = speed;
}
public function run():Void {
this._speed *= 2;
}
public function rest():Void {
this._speed = 0;
}
// getters/setters (accessor methods)
public function get speed():Number {
return this._speed;
}
}
For a full demonstration of how to write methods like the ones in the previous code sample,
see Chapter 7, “Classes,” on page 225. The methods that you use in your code might belong
to a class that is built into the ActionScript language. MovieClip and Math are examples of
top-level classes that you might use in an application. When you use methods from these
classes in your code, they are functions written in the built-in class (similar to the previous
code sample). Alternatively, you could use methods from a custom class that you
wrote yourself.
Functions that don’t belong to a class are called top-level functions (sometimes called predefined
or built-in functions), meaning that you can call them without a constructor. Examples of
functions that are built in to the top level of the ActionScript language are
trace() and
setInterval().