Online PHP editor | output for YF523

<?php function check($input, $length = 4) { $sequence = "abcdefghijklmnopqrstuvwxyz"; $sequence .= substr($sequence, 0, $length - 1); // abcdefghijklmnopqrstuvwxyz is converted to abcdefghijklmnopqrstuvwxyzabc for ($i = 0; $i < strlen($sequence) - $length; $i++) { // loop runs for $i = 0...25 if (strpos($input, substr($sequence, $i, $length)) !== false) { echo sprintf('"%s" contains "%s"' . "\n", $input, substr($sequence, $i, $length)); return true; } } echo sprintf('"%s" is OK' . "\n", $input); return false; } check("youlookgreatbcdetoday"); // "youlookgreatbcdetoday" contains "bcde" check("youlookgreatklmtoday"); // "youlookgreatklmtoday" is OK check("youlookgreattoday"); // "youlookgreattoday" is OK check("youlookgreattodayza"); // "youlookgreattodayza" is OK check("youlookgreattodayzab"); // "youlookgreattodayzab" contains "yzab"