Bug in conditional for loop with an empty array

There appears to be a bug in the for loop with a conditional terminal.
If an empty array is wired to an auto-indexed array input tunnel, an output array tunnel has one element instead of zero.
The array constant on the left is empty.
Top loop without the conditional terminal produces an empty array.
The bottom loop with a never true conditional terminal produces an array with one element
Using LabVIEW version 8.5
Message Edited by TrevMrgn on 05-05-2009 02:01 PM
Solved!
Go to Solution.
Attachments:
For loop bug.png ‏3 KB

Creating the example from scratch, I do not see the error.
Neither do I.
If I add one or more elements to the array (constant or control), then delete them all (using 'Delete Element') the bottom array has one element.
Nup. Still empty.
If I empty the array (using 'Empty Array') both are empty.
Yep.
Also if I create an empty array using 'initialise array' with zero elements, I get one element.
Nup. Still empty.
'Show constant folding' does not appear to change the behaviour, but including a random operation in the loop does.
Agreed that constant folding doesn't cause any odd behaviour. Introducing a random operation (adding two constants) in the loop doesn't either.
I've tried all your methods here Trevor, but I can't replicate this behaviour in 8.5.1 under WinXP SP3. Sorry!
Maybe somebody else will be able to help, or find a useable workaround.
Thoric (CLA, CLED, CTD and LabVIEW Champion)

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Indexing.png ‏4 KB

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RC4 Encryption beta.vi ‏78 KB

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That''s exaclty what I said.
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import java.util.Random;
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Poling_Data_Reader_5i.vi ‏79 KB
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Dynamic component in WHERE-condition for LOOP AT ?

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Edited by: Thomas Zloch on Mar 2, 2010 2:47 PM

I thought it's funny.
And the problem can maybe be solved by using a completely dynamic where-condition, not just a dynamic component.
http://help.sap.com/abapdocu_70/en/ABAPLOOP_AT_ITAB_COND.htm#!ABAP_ADDITION_4@4@
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P.S. meaningless subject enhanced, and please take the time to say hi and please when asking for help. Thanks.

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Edited by: 898552 on Mar 6, 2013 3:07 PM
Edited by: 898552 on Mar 6, 2013 3:09 PM

rp0428 wrote:
>
It's not entering the loop.
>
With the versions of NetBeans I use you can set breakpoints BEFORE and even ON the loop! Being able to set them inside a loop is just a no-cost extra. ;)I know! But you said "IN THE LOOP" :D The poor guy will set his breakpoint in it and think his debugger is broken ;)
Relax - take a deep breath - repeat after me
>
5 more points - 5 more points - 5 more points
>
Congratulations - I see a 'shiny' future for you!
Status Level: Expert (2,495) :DHaha, I hadn't noticed that :D I better be extra helpful now, so I can pop open a bottle of champagne tonight ;)

Bug in conditional for loop with an empty array

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