Why some people say Local Variables are bad...

[yenknip]

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Ray.R wrote:

Yes...  There are many pitfalls..  Maybe like you said, we could have a sub forum. However, we would not want to give the idea that LabVIEW has pitfalls..  All programming languages do..  It's the programmers that create the pitfalls... 😉

Maybe a sub-forum called "Gatchas"...  LOL!  😄

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Good point that.

"How not to do it"

[smercurio_fc]

And now for another example of the pointlessness of the locals:

The other cases in the event structure are basically the same.

from here:http://forums.ni.com/t5/Version-Conversion/Request-to-downconvert-VIs-from-8-5-to-7-1-post-2-2/td-p/...

[altenbach]

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@smercurio_fc wrote:

from here:http://forums.ni.com/t5/Version-Conversion/Request-to-downconvert-VIs-from-8-5-to-7-1-post-2-2/td-p/...

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The correct link is actually here.

Even funnier is the timeout case for the UI. It basically tickles most indicators every 100ms. None are connected, because they are all updated via locals elsewhere. Why? Why? Whyyyy? What a waste of CPU cycles. Omitting the timeout case entirely would not change a thing! 😄

[smercurio_fc]

Thanks for the link correction, altenbach.

Yeah, I got a chuckle out of the Timeout case when I first saw it as well.

[nathand]

How about the first frame of this sequence:

from http://forums.ni.com/t5/LabVIEW/Passing-data-from-RT-host-to-FPGA-through-DMA-FIFO/m-p/1863577#M6325...

[altenbach]

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@nathand wrote:

How about the first frame of this sequence:

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Typical text programmers! 😄

That almost looks like "Local Variable Russian Roulette"! 😮 (A big step above a simple race condition). For the "Temp data array" we have three readers and four writers nearly concurrently. 

You covered the problems nicely in your reply. In addition, I would recommend to transpose before the complex to RE/IM: Only one instance needed.

[Ray.R]

Not only was this one a Rube Goldberg example, it is also an example of Locals abuse. Locals as in Local Variables, not people in the vicinity.

(Seen here)

[crossrulz]

More localitis and sequenceitis (as Altenbach put it).

http://forums.ni.com/t5/LabVIEW/String-box-rejects-input-after-built-with-App-Builder/td-p/2017204

[TiTou]

there is worse than locals... take a look at the VI attached in this post 

[jcarmody]

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@TiTou wrote:

there is worse than locals... take a look at the VI attached in this post 

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My browser's encoding must be off.  I can't understand anything in that post!