I need to use a class callback method on an array inside another method (the callback function belongs to the class).

class Database {

      public function escape_string_for_db($string){
             return mysql_real_escape_string($string);
      }

      public function escape_all_array($array){
             return array_filter($array,"$this->escape_string_for_db");
      }
}

Is this the right way to go about that? (I mean, in terms of the second parameter passed to array_filter)