3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php var_dump(preg_replace('/(?<=[a-z])\L([A-Z])/', '_$1', 'AnaNaaZ'));
based on TKHcZ
Output for 5.3.4 - 5.6.28, 7.0.0 - 7.1.0
Warning: preg_replace(): Compilation failed: PCRE does not support \L, \l, \N{name}, \U, or \u at offset 11 in /in/815HK on line 3 NULL
Output for hhvm-3.10.0 - 3.13.2
Warning: Compilation failed: PCRE does not support \L, \l, \N{name}, \U, or \u at offset 11 in /in/815HK on line 3 NULL
Output for 4.4.0 - 4.4.9, 5.0.5 - 5.3.3
Warning: preg_replace(): Compilation failed: PCRE does not support \L, \l, \N, \U, or \u at offset 11 in /in/815HK on line 3 NULL
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 11 in /in/815HK on line 3 NULL
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 11 in /in/815HK on line 3 NULL