3v4l.org

run code in 300+ PHP versions simultaneously
<?php $nullvar = array( 0 => array('r' => null), 1 => array('r' => 1) ); if (isset($nullvar[0]['r'])) { echo "set"; } else { echo "not set"; } if (is_null($nullvar[0]['r'])) { echo "\nnull"; } else { echo "\nnot null"; }
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 - 5.5.38, 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 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
not set null

preferences:
310.13 ms | 406 KiB | 460 Q