3v4l.org

run code in 300+ PHP versions simultaneously
<<?php namespace MyProject; const con='p'; $classname=namespace\con; function get($classname) { $a = __NAMESPACE__ . '\\' . $classname; echo $a; } ?>
Output for 5.3.0 - 5.3.27, 5.4.0 - 5.4.19
Fatal error: Namespace declaration statement has to be the very first statement in the script in /in/XOVm7 on line 2
Process exited with code 255.

preferences:
178.35 ms | 1395 KiB | 55 Q