Online PHP editor | refs for Lf6NF

<?php $map = []; print "Empty array\n"; var_dump(!isset($map['rollback_action']) || $map['rollback_action'] == 0); $map = false; print "\n\nFalse\n"; var_dump(!isset($map['rollback_action']) || $map['rollback_action'] == 0); $map['rollback_action'] = NULL; print "\n\nNULL value\n"; var_dump(!isset($map['rollback_action']) || $map['rollback_action'] == 0); $map['rollback_action'] = 0; print "\n\n0 value\n"; var_dump(!isset($map['rollback_action']) || $map['rollback_action'] == 0); $map['rollback_action'] = 1; print "\n\n1 value\n"; var_dump(!isset($map['rollback_action']) || $map['rollback_action'] == 0);