3v4l.org

run code in 300+ PHP versions simultaneously
<?php $v = 0; var_dump(isset($v));
Output for 7.3.0 - 7.3.33, 7.4.0 - 7.4.26, 8.0.0 - 8.0.13, 8.1rc1 - rc3
bool(true)

preferences:
27.67 ms | 532 KiB | 13 Q