Online PHP editor | refs for trGMC

<?php $chars = ['A','B','C','F','a','b','c','d','e','f','h','i','j','k','l','o','q','!','?','0','2','3','4','9']; $result = []; $range = [null]; foreach ($chars as $char) { if ($range[0] === null) { $range = [$char]; } elseif (ord($range[1] ?? $range[0]) === ord($char) - 1) { $range[1] = $char; } else { $result[] = implode('-', $range); $range = [$char]; } } if ($range[0] !== null) { $result[] = implode('-', $range); } var_export($result);