php __get(),__set()函数来实现对属性的访问

class class_name
{
  var $attribute;
  function __get($name)
  {
   return $this -> $name;
  }
  function __set($name,$value)
  {
    $this -> $name = $value;
  }

}
$a = new class_name();
$a -> attribute = 5;//__set()设置属性值
$a -> attribute; //__get()检查属性值