3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php define("__FLAG__", 1); define("__DEBUG__", __FLAG__); // the flag is hidden here. find it lol if(1 === __DEBUG__){ echo "development server"; }else{ echo "production server"; }
based on Wduk5
Output for 5.6.0 - 7.3.0alpha1
development server