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Topic Title: string null,empty, void?
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Created On: 15-Nov-2004 19:10
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 15-Nov-2004 19:10
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Louie Landale

Posts: 2070
Joined: 12-Sep-2002

I don't recall much from school about data storage and don't know squat about "C" or "C++".

I'm getting an error after reading a history.oldvalue parameter of a particular History Record. When I use the string later I'm getting "null string parameter passed" errors. It seems to faile in one program but not in another. Odd. Anyway, attempting to trap the error with noError()/lastError() didn't work. I suspect the History record may be corrupted since it shows modifying Object text from nothing to nothing (but perhaps its really from empty to null).

However, when I insert the following line I no longer get the error:
if (null ValueOld) ValueOld = ""

It makes me wonder if I don't understand the difference between "null" and "empty".

Anybody got any ideas?

- Louie
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 16-Nov-2004 17:17
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Tony Goodman

Posts: 1098
Joined: 12-Sep-2002

Louie,
Wish I have read the forums this morning. I thought it was me going mad.

I have and I spent all morning trying to figure this one out.

have you just moved to version 7.1?

I am getting the same "Null string parameter" error on 7.1, but running the same code on 7.0 works fine.

In desperation I came up with the same work-around as you:
if (null str) str = ""

But this makes no sense.

I remain confused.

I am sure this is a bug, but I have so far failed to reproduce the error in a simple self-contain piece of code that I can send to support.

-------------------------
Tony Goodman
http://www.smartdxl.com
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 18-Nov-2004 04:18
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Tom Cook

Posts: 4
Joined: 15-Nov-2004

Louie, null means no object, "" means an object that is an empty string. It is the difference between an empty box ("") and no box at all (null).
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