3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = 100; $b = $a; $a = null; var_dump(is_set($a)); var_dump($b);
based on u4AdI
Output for 7.0.0 - 7.2.0
Fatal error: Uncaught Error: Call to undefined function is_set() in /in/nMWSj:8 Stack trace: #0 {main} thrown in /in/nMWSj on line 8
Process exited with code 255.
Output for 5.5.0 - 5.6.25
Fatal error: Call to undefined function is_set() in /in/nMWSj on line 8
Process exited with code 255.