3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array('dupa' => 2, 'zupa' => 3); unset($a['dupa']); var_dump($a);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 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 - 5.5.36, 5.6.0 - 5.6.22, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.29 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.30, 8.0.0 - 8.0.22, 8.1.0 - 8.1.9
array(1) { ["zupa"]=> int(3) }

preferences:
80.88 ms | 412 KiB | 5 Q