How is this code adding adding movieClips to the stage

programming flash
1

Hi,

I’m currently reading the book Learning Actionscript 3.0 and I cannot figure how this was done. In chapter 6, there is an example of Ingeritace, Encapsulation etc. where there is a class called Vehicle and from that class a few more classes were created Car, Truck etc. and everything make sense but there is something I don’t know understand, there are two MovieClips that are added to the stage at run time and I can’t figure out how those clips were added to the stage, I tried doing my own version and I tried exporting these MovieClips checking the Export for actionscript option under propeties but it doesn’t work.

Can some who have read this book please tell me how this movieClips are added to the stage (car and truck images)?

package standard.testing{
	import flash.display.MovieClip;
	import flash.events.Event;


	public class Vehicle extends MovieClip {

		public var _fuelAvailable:Number;
		public var _mileage:Number;
		public var _milesTraveled:Number=0;
		public var _go=Boolean;

		public function Vehicle(mpg:Number=20, fuel:Number=15) {
			_mileage=mpg;
			_fuelAvailable=fuel;
			this.addEventListener(Event.ENTER_FRAME,onLoop,false,0,true);
		}

		public function onLoop(evt:Event) {
			if (_go==true) {
				_fuelAvailable--;
				_milesTraveled+=_mileage;

				if (_fuelAvailable<1) {
					this.removeEventListener(Event.ENTER_FRAME,onLoop);
				}
				trace(this, _fuelAvailable,_milesTraveled);
				this.x=_milesTraveled;
			}
		}
		public function go() {
			_go=true;
		}

	}
}

Class created from the Vehicle class:

package {

	import flash.display.MovieClip;
	import flash.events.Event;
	
	public class Car extends Vehicle {

		public function Car(mpg:Number, fuel:Number) {
			_gasMileage = mpg;
			_fuelAvailable = fuel;
			_tires = new Tires("highperformance");
			trace(this +" has " + _tires.type + " tires");
		}
		
		public function openSunroof () {
			trace(this, "opened sunroof");
		}
	}
}

Fla file:

var compact:Car = new Car(21, 18);
compact.x = 20;
compact.y = 20;
addChild(compact);
compact.openSunroof();