3v4l.org

run code in 300+ PHP versions simultaneously
<?php namespace Amp { function coroutine() { print "OK"; } } namespace { use function Amp\coroutine as c; c(); }
Output for 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 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 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
OK
Output for 5.5.0 - 5.5.35
Parse error: syntax error, unexpected 'function' (T_FUNCTION), expecting identifier (T_STRING) or \\ (T_NS_SEPARATOR) in /in/gbVZ7 on line 10
Process exited with code 255.
preferences:
201.97 ms | 401 KiB | 260 Q