note 125026 added to function.preg-replace

Note that the replacement string using the ${n} notation for a group identifier (rather than the $n notation) must be in a SINGLE quoted string: $replacement = '${1}1,$3'; // Correct - Single Quoted $replacement = "${1}1,$3"; // Incorrect - Double Quoted $replacement = "$1 one , $3"; // Correct - Double Quoted but with $n notation. This might sneak up on you, because it is not an error to use "${1}". The double quotes allow a string that contains variable interpolation, and the braces make the variable a PHP "Variable-Variable". In the above example the undefined ${1} will evaluate to NULL rather than the replaced string. Valid PHP, but not what you wanted. ---- Server IP: 45.112.84.4 Probable Submitter: 38.142.137.34 (proxied: 2001:569:72cc:6100:e950:8412:a11b:ab7f) ---- Manual Page -- http://php.net/manual/en/function.preg-replace.php Edit -- https://master.php.net/note/edit/125026 Del: integrated -- https://master.php.net/note/delete/125026/integrated Del: useless -- https://master.php.net/note/delete/125026/useless Del: bad code -- https://master.php.net/note/delete/125026/bad+code Del: spam -- https://master.php.net/note/delete/125026/spam Del: non-english -- https://master.php.net/note/delete/125026/non-english Del: in docs -- https://master.php.net/note/delete/125026/in+docs Del: other reasons-- https://master.php.net/note/delete/125026 Reject -- https://master.php.net/note/reject/125026 Search -- https://master.php.net/manage/user-notes.php