On Sun, 13 Jun 2004 20:08:48 +0900, you wrote:

>In fact this has nothing to do with procedural vs. OO.  The way how
>variables (locations) and values are related is completely orthogonal to the
>nature of the language (procedural or OO).

in my particular case i'm thinking black box approach. i don't want
the variable to 'exist' any more.

i don't know if that's how it's thought of in perl, but when i
undef($x), $x is no longer there for me to use unless i assign it
something, and i can test that it isn't with:

 if ! defined($x) # do something.

as long as ruby 'acts' the same way, it's all i need.