Can you undefine or change a constant in PHP?

Question

Can you undefine or change a constant in PHP?

Answer 1

If you absolutely need to do this (although I wouldn't recommend it as others have stated) you could always use Runkit.

http://www.php.net/manual/en/function.runkit-constant-redefine.php

http://www.php.net/manual/en/function.runkit-constant-remove.php