[MEMO]未設定の検出

/**
 * Copyright sekiryou ( http://wonderfl.net/user/sekiryou )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/xxMm
 */

/**
* 未設定の検出
* @author Masayuki Komatsu / sekiryou.com
* http://twitter.com/sekiryou_com
*/

package {
    import flash.display.Sprite;
    public class test extends Sprite {
        public function test() {
            var test:Sprite = new Sprite();
            var color:Number = undefined;
            if (color == 0) {
                trace("0");
                test.graphics.beginFill(color);
                //circle
                test.graphics.drawCircle(10, 10, 10);
                test.graphics.endFill();
                addChild(test);
            } else {
                trace("undefined");
                test.graphics.beginFill(color);
                //rect
                test.graphics.drawRect(10, 10, 10, 10);
                test.graphics.endFill();
                addChild(test);
            }
            //
            check(3);
            check(0);
            check();
        }
        private function check(tmp:Number = undefined):void {
            if (tmp || tmp == 0) {
                trace("defined:", tmp);
            } else {
                trace("undefined");
            }
        }
    }
}