3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php setlocale(LC_ALL, 'ru_RU.cp1251'); echo preg_replace ( '/[^\p{L}\d]/iu', '_', 'ёйцукенгшщзхъфывапролджэячсмитьбю1234567890' );
Output for 4.4.0 - 4.4.9, 5.0.5 - 7.2.0
ёйцукенгшщзхъфывапролджэячсмитьбю1234567890
Output for 4.3.11, 5.0.0 - 5.0.4
Warning: preg_replace(): Compilation failed: PCRE does not support \L, \l, \N, \P, \p, \U, \u, or \X at offset 3 in /in/VAvDC on line 3
Output for 4.3.0 - 4.3.10
Warning: Compilation failed: PCRE does not support \L, \l, \N, \P, \p, \U, \u, or \X at offset 3 in /in/VAvDC on line 3