3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $_SESSION["X"] = "Hello"; unset($_SESSION["X"]); echo $_SESSION["X"];
based on eDq6v
Output for 5.3.0 - 7.2.0
Notice: Undefined index: X in /in/NujHt on line 5
Output for 4.3.0 - 5.2.17
Notice: Undefined index: X in /in/NujHt on line 5