3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Foo {} class_alias('Foo', '0'); $className = '0'; var_dump(class_exists('0')); var_dump(new $className);
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
bool(true) object(Foo)#1 (0) { }
preferences:
132.32 ms | 408 KiB | 5 Q