MACROMEDIA FLASH 8-ACTIONSCRIPT 2.0 LANGUAGE Reference page 220

The keyword was created specifically to enable compile-time type checking for
intrinsic
built-in classes and objects, and global variables and functions. This keyword was not meant
for general purpose use, but may be of some value to developers seeking to enable compile-
time type checking with previously defined classes, especially if the classes are defined using
ActionScript 1.0.
This keyword is supported only when used in external script files, not in scripts written in the
Actions panel.
Availability: ActionScript 2.0; Flash Player 6
Example
The following example shows how to enable compile-time file checking for a previously
defined ActionScript 1.0 class. The code will generate a compile-time error because the call
myCircle.setRadius()
can avoid the error by changing the parameter to a
to ).
"10" 10
// The following code must be placed in a file named Circle.as
// that resides within your classpath:
intrinsic class Circle {
var radius:Number;
function Circle(radius:Number);
function getArea():Number;
function getDiameter():Number;
function setRadius(param_radius:Number):Number;
}
// This ActionScript 1.0 class definition may be placed in your FLA file.
// Circle class is defined using ActionScript 1.0
function Circle(radius) {
this.radius = radius;
this.getArea = function(){
return Math.PI*this.radius*this.radius;
};
this.getDiameter = function() {
return 2*this.radius;
};
this.setRadius = function(param_radius) {
this.radius = param_radius;
}
}
// ActionScript 2.0 code that uses the Circle class
var myCircle:Circle = new Circle(5);
trace(myCircle.getArea());
trace(myCircle.getDiameter());
myCircle.setRadius("10");
220 ActionScript language elements
sends a value as a parameter instead of a
String
value (for example, by changing
Number
value. You
Number