3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $f = function() {}; var_dump(function_exists($f));
based on tmrnk
Output for 5.6.0 - 5.6.30, hhvm-3.15.4, 7.0.0 - 7.3.0beta1
Warning: function_exists() expects parameter 1 to be string, object given in /in/lHgZH on line 3 NULL