hasOwnProperty的误区

 

package
{
 import flash.display.Sprite;
 public class Test extends Sprite
 {
  private var a : Boolean;
  public var b : Boolean;
  internal var c:Boolean;
  private function test1() : void
  {
  }
  public function test2() : void
  {
  }
  
  internal function test3():void
  {
   
  }
  public function Test()
  {
   super();
   trace( this.hasOwnProperty( "a" ));//false
   trace( this.hasOwnProperty( "b" ));//true
   trace( this.hasOwnProperty( "c" ));//false
   trace( this.hasOwnProperty( "test1" ));//false
   trace( this.hasOwnProperty( "test2" ));//true
   trace( this.hasOwnProperty( "test3" ));//false
  }
 }
}

hasOwnProperty只能判断public权限的属性和方法是否存在，非public的属性和方法一律都为false，如果没注意这点，很容易导致动态获取属性或方法时程序出现所谓的bug