3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php if (empty($mystring)) { echo "empty\n"; } if ($mystring == null) { echo "null\n"; // Undefined variable } if (!isset($mystring)) { echo "unset\n"; }
Output for 5.0.4 - 7.2.11
empty Notice: Undefined variable: mystring in /in/DmaOr on line 5 null unset
Output for 4.3.0 - 5.0.3
empty Notice: Undefined variable: mystring in /in/DmaOr on line 5 null unset