3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php error_reporting(E_ALL); function out(&$x) { $x = 'out'; } out($c = NULL); var_dump($c);
Output for 7.0.0 - 7.1.0
Notice: Only variables should be passed by reference in /in/JfD5Q on line 4 NULL
Output for hhvm-3.10.0 - 3.12.0
Strict Warning: Only variables should be passed by reference in /in/JfD5Q on line 4 NULL
Output for 5.4.0 - 5.6.28
Strict Standards: Only variables should be passed by reference in /in/JfD5Q on line 4 NULL
Output for 5.1.2 - 5.3.29
NULL
Output for 4.3.0 - 5.1.1
string(3) "out"