code: function getValue($el) {
      return $el.is('[type="checkbox"]') ? $el.prop('checked')                                     :
             $el.is('[type="radio"]')    ? !!$('[name="' + $el.attr('name') + '"]:checked').length :
             $el.is('select[multiple]')  ? ($el.val() || []).length                                :
                                           $el.val()
    }
docs: VALIDATOR CLASS DEFINITION ==========================