- define: documentation ( source)
<?php
namespace Foo;
define('Foo\\null', true, true);
define('Foo\\false', true, true);
define('Foo\\true', false, true);
echo 'null:';if (null) echo "TRUE";else echo "FALSE";
echo "\nfalse:";if (false) echo "TRUE";else echo "FALSE";
echo "\ntrue:";if (true) echo "TRUE";else echo "FALSE";