3v4l.org

run code in 300+ PHP versions simultaneously
<?php $old = 'james,john,mark,luke,'; $users = 'james,john,mark,luke,mary,david'; $expr = rtrim(preg_replace('/\,/', '|', $old), '|'); $newstr = preg_replace("/$expr/i", '', $users); echo trim($newstr, ',');
Output for 5.5.0 - 5.5.36, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
mary,david

preferences:
184.99 ms | 404 KiB | 216 Q