Online PHP editor | refs for 4H7GJ

<?php echo "Normal match:\n"; preg_match('/two/', 'two', $match, PREG_UNMATCHED_AS_NULL); var_dump($match); echo "Unmatched $1 is always reported as null:\n"; preg_match('/(one)?two/', 'two', $match, PREG_UNMATCHED_AS_NULL); var_dump($match); preg_match('/two(three)?/', 'two', $match, PREG_UNMATCHED_AS_NULL); var_dump($match); preg_match('/(one)?(two)/', 'two', $match, PREG_UNMATCHED_AS_NULL); var_dump($match); echo "Unmatched $2 is also reported as null:\n"; preg_match('/(two)(three)?/', 'two', $match, PREG_UNMATCHED_AS_NULL); var_dump($match);