3v4l.org

run code in 300+ PHP versions simultaneously
<?php preg_match('/^[^.]*\.(?=\w+\.\w+$)/','subdomain.example.com',$matches); $subdomain = isset($matches[0]) ? trim($matches[0],'.') : ''; echo $subdomain;
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.17, 8.5.0 - 8.5.2
subdomain

preferences:
100.4 ms | 407 KiB | 5 Q