sampletypecheck.as

《Flash AS3殿堂之路》光盘源码 学习ActionScript 3.0

package org.kingda.book.basicoop.polymorphism
{
	import flash.display.Sprite;
	public class SampleTypeCheck extends Sprite	
	{
		public function SampleTypeCheck() {
			var a:Number = 123;
			var b:String = "123";
			var c:Array	 = [1,2,3];			
			var base:Base 		= new Base();
			var ext	:Extender	= new Extender();			
			trace (a is Number);	//输出:true
			trace (a is String);	//输出:false
			
			trace (b is String);	//输出:true
			trace (b is Number);	//输出:false
			trace (c is Array);		//输出:true
			
			trace (a is Object); 	//输出:true
			trace (b is Object); 	//输出:true
			trace (c is Object);	//输出:true
			
			trace (base is Base); 	//输出:true
			trace (base is Extender);//输出:false
			trace (ext is Base);	//输出:true
			trace (ext is Extender);//输出:true			
		}
	}
}
class Base { 
	public function Base() {
		trace ("Type:Base")
	}
}
class Extender extends Base{}