3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $str = 'hello\_world\_again'; $str = preg_replace('/\_(.)/e', '$0', $str); echo $str;
Output for 7.0.0 - 7.1.0
Warning: preg_replace(): The /e modifier is no longer supported, use preg_replace_callback instead in /in/eLX0o on line 3
Output for hhvm-3.12.0
Notice: Use of undefined constant _w - assumed '_w' Notice: Use of undefined constant _a - assumed '_a' hello\_world\_again
Output for hhvm-3.10.0

Process exited with code 153.
Output for 5.5.24 - 5.6.28
Deprecated: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in /in/eLX0o on line 3 Notice: Use of undefined constant _w - assumed '_w' in /in/eLX0o(3) : regexp code on line 1 Notice: Use of undefined constant _a - assumed '_a' in /in/eLX0o(3) : regexp code on line 1 hello\_world\_again
Output for 4.3.0 - 5.4.45
Notice: Use of undefined constant _w - assumed '_w' in /in/eLX0o(3) : regexp code on line 1 Notice: Use of undefined constant _a - assumed '_a' in /in/eLX0o(3) : regexp code on line 1 hello\_world\_again