Negating specific words with regexes isn't a good practice (see a deep discussion here: http://www.perlmonks.org/?node_id=588315), in your case I would resolve it like this: <?php $s = 'cats i saw a cat and a dog'; var_dump(preg_split('/(dog|cat)/', $s, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY)); ?> That will output: array(5) { [0]=> string(3) "cat" [1]=> string(10) "s i saw a " [2]=> string(3) "cat" [3]=> string(7) " and a " [4]=> string(3) "dog" } Then you just have to go through the result array of preg_split and concatenate every "cat" and "dog". Regards, Jonathan On Sat, Aug 22, 2009 at 12:32 PM, דניאל דנון<danondaniel@xxxxxxxxx> wrote: > Lets assume I have the string "cats i saw a cat and a dog" > i want to strip everything except "cat" and "dog" so the result will be > "catcatdog", > using preg_replace. > > > I've tried something like /[^(dog|cat)]+/ but no success > > What should I do? > > -- > Use ROT26 for best security > -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
