3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 1; unset($a); var_dump(isset($a)); var_dump(!isset($a)); var_dump(empty($a)); var_dump(is_null($a));
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
bool(false) bool(true) bool(true) Warning: Undefined variable $a in /in/RtIm9 on line 11 bool(true)
Output for 5.0.4 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
bool(false) bool(true) bool(true) Notice: Undefined variable: a in /in/RtIm9 on line 11 bool(true)
Output for 7.3.32 - 7.3.33
bool(false) bool(true) bool(true) bool(true)
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.3
bool(false) bool(true) bool(true) Notice: Undefined variable: a in /in/RtIm9 on line 11 bool(true)
preferences:
286.11 ms | 402 KiB | 460 Q