3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php function f(&$r) { $r++; } $r = 1; $r = f(f($r)); echo $r;
Output for 7.0.0 - 7.2.6
Notice: Only variables should be passed by reference in /in/UHRIm on line 8
Output for 5.1.0 - 5.6.28
Strict Standards: Only variables should be passed by reference in /in/UHRIm on line 8
Output for 5.0.5
Fatal error: Only variables can be passed by reference in /in/UHRIm on line 8
Process exited with code 255.
Output for 4.3.0 - 5.0.4