On Sat, 17 Dec 2005, Darren Duncan wrote:
Undef means "don't know", which is distinct from "zero", because in the latter case we explicitly have a value of zero.
But when we don't know we can, and generally do, make reasonable _guesses_.
Experience has shown that 0 or '' according the context are ehm, not only reasonable, but even good guesses that work most of the time. So much that we can safely rely on them. Or if they don't, then it's easy to explicitly take care of that particular undef like you suggest.
Also, let undef be an "I don't know" as much as you like: still you can't negate that it is invariably associated psychologically with a feeling of 'nothingness' - indeed it's nothing else; or possibly anything else at the same time...
Michele -- Gavin: Oliver, my father used to say that a man can never outdo a woman when it comes to love and revenge. - The War of the Roses (1989)
