Hi, The replaced string is returned by the function. This works. $str = "test test2"; $str2 = preg_replace('/ /', ',', $str); If your are doing simple replacements like this you should use str_replace() it's much faster! $str = "test test2"; $str2 = str_replace(' ', ',', $str); - Frank > How do I use preg_replace to replace a space (" ") with a comma (",")? > > i am using: > > preg_replace('/ /', ',', $string). > > this isn't working. > > > -- > Gerardo S. Rojas > mailto: grojas@strategicinc.com > > -- PHP Windows Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php