note 125713 added to ref.strings

Hello, I'm having problem with this code that gets row info: $course_title = trim(substr($data[1], 0, 50)); Message: ErrorException: Undefined offset: 1 If there another way to fix this? ---- Server IP: 45.112.84.4 Probable Submitter: 45.91.159.166 (proxied: 185.245.86.55) ---- Manual Page -- http://php.net/manual/en/ref.strings.php Edit -- https://master.php.net/note/edit/125713 Del: integrated -- https://master.php.net/note/delete/125713/integrated Del: useless -- https://master.php.net/note/delete/125713/useless Del: bad code -- https://master.php.net/note/delete/125713/bad+code Del: spam -- https://master.php.net/note/delete/125713/spam Del: non-english -- https://master.php.net/note/delete/125713/non-english Del: in docs -- https://master.php.net/note/delete/125713/in+docs Del: other reasons-- https://master.php.net/note/delete/125713 Reject -- https://master.php.net/note/reject/125713 Search -- https://master.php.net/manage/user-notes.php