added param types

classes/bulkenrol_form.php

@@ -137,7 +137,7 @@ public function validation($data, $files) {
     /**
      * Returns the name of a fieldoption without its table prefix
      * @param $fieldoption string fieldname with type prefix
-     * @return string name of field without type prefix
+     * @return bool|mixed|string name of field without type prefix
      * @throws \UnexpectedValueException Field is not prefixed by c_ or u_
      * @throws \dml_exception Database connection error
      */
@@ -159,7 +159,7 @@ private function get_fieldname($fieldoption) {
      * @param $search string needle to search for
      * @param $replace string replacement for needle
      * @param $subject string subject string to search
-     * @return string subject string with the last occurence of the needle replaced
+     * @return string|string[] subject string with the last occurence of the needle replaced
      */
     private function str_last_replace($search, $replace, $subject) {
         $pos = strrpos($subject, $search);