3v4l.org

run code in 300+ PHP versions simultaneously
<?php $prom = []; if($prom == null) { echo "TRUE"; }
Output for 7.0.0 - 7.0.23, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.26, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
TRUE

preferences:
95.45 ms | 407 KiB | 5 Q