flash as3 克隆数组

克隆数组分浅副本和深副本。
浅副本有个缺点：数组元素是对象的话，则仅复制指向对象的引用而非对象本身。对对象所做的任何更改都会在两个数组中反映出来。

package {
	import flash.display.Sprite;
	public class ArgTest extends Sprite {
	    public function ArgTest() {
		var user:Object = new Object();
		user.name = "li";
		var letters:Array = new Array("a", "b", "c", "d", "e", user);
		var someLetters:Array = letters.slice(0);
		letters[letters.length -1 ].name = "cheng";
		trace(letters);     // a,b,c,d,e,f
		trace(someLetters); // c,d,e,f
		trace(someLetters[someLetters.length -1 ].name);

	  }
        }
}