Edit report at https://bugs.php.net/bug.php?id=63818&edit=1
ID: 63818 Comment by: danielklein at airpost dot net Reported by: dkadosh at affinegy dot com Summary: Need option to search in array keys instead of values Status: Open Type: Feature/Change Request Package: PCRE related Operating System: any PHP Version: 5.3.20 Block user comment: N Private report: N New Comment: How about this? <?php function preg_grep_keys($pattern, $input, $flags = 0) { return array_intersect_key($input, array_flip(preg_grep($pattern, array_keys($input), $flags))); } ?> Previous Comments: ------------------------------------------------------------------------ [2012-12-20 17:06:30] dkadosh at affinegy dot com Description: ------------ --- >From manual page: http://www.php.net/function.preg-grep --- I'm asking for an extra flag to this function, to cause it to do its search in the array keys rather than in the values. While there's a comment in the above page of how to "post-process" preg_grep() results to achieve this, I'd rather it be done in C (inside the PCRE code) than PHP for performance reasons. I thought about something like this: $a = array_flip( preg_grep('/Version$/', array_flip($aParams)) ); which would almost return what I want, HOWEVER it has two problems: 1) If certain values of $aParams are duplicated, the first array_flip() will "lose" those rows in the array. 2) I'd incur a sizeable CPU and memory hit by calling array_flip, which duplicates the array(s) in RAM. Test script: --------------- The current work-around: function preg_grep_keys( $pattern, $input, $flags = 0 ) { $keys = preg_grep( $pattern, array_keys( $input ), $flags ); $vals = array(); foreach ( $keys as $key ) { $vals[$key] = $input[$key]; } return $vals; } ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=63818&edit=1