Online PHP editor | refs for tIb9i

<?php function a($a, $b = null) { var_dump($a); var_dump(isset($a)); var_dump(is_null($a)); var_dump($b); var_dump(isset($b)); var_dump(is_null($b)); } a(); print "---"; a(1); print "---"; a(1,2); print "---"; a(null); print "---"; a(null, null); print "---";