According to the PHP manual, the u modifier of PCRE regular expressions enables UTF-8 support for both the pattern and the subject string.
Considering this, is there any difference between using PCRE expressions with the u modifier and the corresponding mb_* multibyte string functions? (Assuming that all strings are UTF-8 encoded.)
As an example, consider preg_split vs mb_split: Both
preg_split('/' . $pattern . '/u', $string);
and
mb_split($pattern, $string);
seem to return identical results. So, which one should be preferred? Does it even matter?