3v4l.org

run code in 300+ 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 - 7.4.30, 8.0.0 - 8.0.22, 8.1.0 - 8.1.9
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:
54.71 ms | 410 KiB | 5 Q