A Null String

[armsys]

Let>x=
Is x technically a null string? From the MS Deubg > Watch list, it show x is null string. BTW, what's the data type of x in this case?

[JRL]

Let>x=
Is x technically a null string?

Yes, at least I believe it to be true. To prove it use the "set variables on the fly" technique you spoke of recently. If we set x to nul then set nul to a value through the on the fly assignment using "x", all subsequent variables set to nul will have the new value of nul.

For example:

Code: Select all

Let>x=
Let>%x%=2
Let>xx=
MDL>xx

I could be wrong but I believe this proves that setting a variable in the form

Let>x=

actually sets the variable to something and THAT something is nothing (nul), unless you change "nothing" to another value.

Hope this makes sense... (not even sure it makes sense to me...)

[armsys]

Hi JRL,
Thanks for conceiving such a wonderful thought provocative sample script. I'm dumbfounded by the discovery that, referring to line 2 in your script, 2 is assigned to NOTHING. And, in line 3, you assign the NOTHING to XX. In line 4, since you've already assigned 2 to the NOTHING, the 2 is now assigned to XX. That's a big eye-opener.

That's exactly why I ask in my originating post what data type is assigned to the NOTHING.

Another discovery: there's no way to kill variables in MS script (to release memory).

[Marcus Tettmar]

Let>x=

Actually sets x to an EMPTY STRING.

You may find it conceptually easier to understand if you do:

Let>x={""}

In VB it would be:

x = ""