3v4l.org

run code in 500+ PHP versions simultaneously
<?php echo preg_match('/Я/ui', 'я'); echo preg_match('/(?=Я)/ui', 'я'); echo preg_match('/Л/ui', 'л'); echo preg_match('/(?=Л)/ui', 'л');
Output for 7.4.6 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
1111
Output for 7.1.25 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.5
1011
preferences:
113.54 ms | 1471 KiB | 4 Q