note 96202 added to function.substr

One has to note that substr() always returns false on an empty string. The line "If string is less than or equal to start characters long, FALSE will be returned." is a little bit misleading since start can be negative. substr('',-1) returns false as opposed to an empty string. For positive starts the documentation is consistent. I cannot stretch enough that substr() returns false on an empty string. The documentation does not state that explicitly. So if you're doing something like this: <?PHP function extract_numbers($input_text) { while (($char = substr($input_text, 0, 1)) !== false) { if (is_numeric($char)) { $result .= $char; } $input_text = substr_replace($input_text, '', 0 , 1); } return $result; } ?> be sure to check on false and not on an empty string ---- Server IP: 212.124.37.9 Probable Submitter: 92.78.0.203 ---- Manual Page -- http://www.php.net/manual/en/function.substr.php Edit -- https://master.php.net/note/edit/96202 Del: integrated -- https://master.php.net/note/delete/96202/integrated Del: useless -- https://master.php.net/note/delete/96202/useless Del: bad code -- https://master.php.net/note/delete/96202/bad+code Del: spam -- https://master.php.net/note/delete/96202/spam Del: non-english -- https://master.php.net/note/delete/96202/non-english Del: in docs -- https://master.php.net/note/delete/96202/in+docs Del: other reasons-- https://master.php.net/note/delete/96202 Reject -- https://master.php.net/note/reject/96202 Search -- https://master.php.net/manage/user-notes.php