How can I find the user role using user id in moodle

I am new to `Moodle` and I have the following code: $userDetails = $DB->get_record('user', array('id' => $singleuser->userid)); var_dump($userDetails); echo $userDetails->firstname." ".$userDetails->lastname It is having the details of user table in `Moodle`. How can I find the role like Teacher, Admin, student? Here I am having the userids `$singleuser->userid` . I am printing Users full name . I need the role along with it like the following: echo $userDetails->firstname." ".$userDetails->lastname.$role. How can I find role? Please guide me. **Moodle Version: 2.9.1**