3v4l.org

run code in 300+ PHP versions simultaneously
<?php if (!class_exists(OptionalInterface::class)) { interface OptionalInterface {} } class Expression implements OptionalInterface {}
Output for 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
preferences:
59.88 ms | 968 KiB | 4 Q