3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr = []; $arr['key'] = NULL; var_dump(isset($arr['key'])); //bool(false) var_dump(is_null($arr['key'])); //bool(true) var_dump(is_null($arr['any_key']));

preferences:
52.63 ms | 402 KiB | 5 Q