Online PHP editor | output for 6At9F

<?php function consecutiveCharCount($string) { $lcString = strtolower($string); $prevChar = $lcString[0]; $currentLen = 0; $maxLen = 0; $ascending = null; for ($i = 1; $i < strlen($lcString); $i++) { $diff = ord($lcString[$i]) - ord($prevChar); if ($diff == 1) { if ($ascending !== true) { $ascending = true; $currentLen = 0; } $currentLen += 1; } elseif ($diff == -1) { if ($ascending !== false) { $ascending = false; $currentLen = 0; } $currentLen += 1; } else { $currentLen = 0; } $maxLen = max($maxLen, $currentLen); $prevChar = $lcString[$i]; } return $maxLen; } echo consecutiveCharCount("abcdegionoas"); echo consecutiveCharCount("EDCb00808asabc"); echo consecutiveCharCount("asg7898"); echo consecutiveCharCount("asgab876567asfon");