3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php function wer(&$x) { echo $x; } $e = 'ert'; call_user_func('wer', $e);
Output for 7.1.0 - 7.3.1
Warning: Parameter 1 to wer() expected to be a reference, value given in /in/QT9Gd on line 6 ert
Output for 5.4.28 - 5.6.30, 7.0.0 - 7.0.20
Warning: Parameter 1 to wer() expected to be a reference, value given in /in/QT9Gd on line 6
Output for hhvm-3.15.4
ert