preg_match, UTF-8 and whitespace

Just a quick note, be careful when using the whitespace character \s in preg_match when operating with UTF-8 strings. Suppose you have a string containing a dagger symbol. When you try to strip all whitespace from the string like this, you will end up with an invalid UTF-8 character: $ php -r 'echo preg_replace("#\s#", "", […]