3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = "bar"; $$foo = "whatever"; $$$foo = "wtf"; var_dump($foo, $$foo, $$$foo);
Output for 5.4.2 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
string(3) "bar" string(8) "whatever" string(3) "wtf"
preferences:
193.64 ms | 404 KiB | 225 Q