3v4l.org

run code in 500+ PHP versions simultaneously
<?php class A {} class B {} interface i { function foo(A $a) : A ; } class C implements i { function foo(A|B $a) : A&B {} }
Output for 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11

preferences:
27.83 ms | 1151 KiB | 7 Q