Online PHP editor | refs for NLBBZ

<?php $tag = "MU"; $strings = [ 'D109 MU, worked from home today', 'Walked the dog, later took the kids to swimming. D110 MU. Went to the gym in the evening for the 9th time this month.' ]; foreach ($strings as $string) { echo "\n---\n" , preg_match("~D\K\d+(?= $tag)~", $string, $out) ? $out[0] : 'fail'; }