3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $arr = array('key' => null); var_dump(isset($arr[$key]));
Output for 5.0.4 - 7.2.0
Notice: Undefined variable: key in /in/p0DQ3 on line 4 bool(false)
Output for 4.3.0 - 5.0.3
Notice: Undefined variable: key in /in/p0DQ3 on line 4 bool(false)