note 77973 added to function.preg-replace

Be carefull with substitutions Following code should remove all single letters near spaces and remove unnecesary duplicated spaces: <?php $f = " A B C Defg "; $f = preg_replace('/\s[^\s]\s/', ' ', $f); echo trim(preg_replace('/\s\s+/', ' ', $f)) . "\n"; ?> Will result: B Defg Why the letter "B" has not been removed? This is because matched pattern cannot match the same part of text twice, and so it will be as (space-A-space) is matched, then next is (space-C-space) Regards ---- Server IP: 212.124.37.9 Probable Submitter: 82.160.181.2 ---- Manual Page -- http://www.php.net/manual/en/function.preg-replace.php Edit -- https://master.php.net/note/edit/77973 Del: integrated -- https://master.php.net/note/delete/77973/integrated Del: useless -- https://master.php.net/note/delete/77973/useless Del: bad code -- https://master.php.net/note/delete/77973/bad+code Del: spam -- https://master.php.net/note/delete/77973/spam Del: non-english -- https://master.php.net/note/delete/77973/non-english Del: in docs -- https://master.php.net/note/delete/77973/in+docs Del: other reasons-- https://master.php.net/note/delete/77973 Reject -- https://master.php.net/note/reject/77973 Search -- https://master.php.net/manage/user-notes.php