Can a For Loop run in the decrementing mode?

[Scott64]

I'm trying to make a For loop decrement but can't seem to find anything out on the web.  Is this possible?

Thanks

Scott

[Darren]

Hi Scott,

For Loops will always increment their iteration count, there's no way to change that.  However, you could do some pretty simple math on the total count and the iteration terminal in order to get a decrementing value each iteration of the loop.

-D

[LV_Pro]

As the previous poster suggests you just need a starting value, and then the "iteration count" subtracted from that number will give you the decrement. If you are using the autoindex of an array to determine the number of iterations you can get the starting number from the "N" in the upper left corner (similarly, if you aren't autoindexing that is where you would wire the number of indexes to perform) and then subtracting the iteration number from that number will give you a decrement.

P.M.

[Scott64]

I did think about the math, but it wouldn't work in my case.  I guess I'm just going to have to try using a while loop instead.

Thanks for the help

Scott

[Darren]

Hey Scott,

I'm curious about your use case.  Can you describe in a little more detail what you're trying to do, and why a For Loop won't suffice?

Thanks,

-D

[Dennis_Knutson]

Whether you use a for loop or a while loop, decrementing is easy with a shift register. Here's an example that does it with either a constant wired to the count terminal or an auto-indexed array input.

[Elsa Fung]

This will count from 25 to 1 (inclusive)

[John Rich]

I, too, am curious as to why you don't think that you can do it in a for loop.  If you could give more details with regard to your particular problem I believe that either a for loop or a while loop could be made to suffice. 

[tbob]

Elsa's solution is definitely worth 5 stars.  It is so easy to overlook very simple solutions.  I was thinking along the lines of Dennis's solution, and here comes Elsa to show us how easy it can be.  Great job Elsa.

[Dennis_Knutson]

I agree though I must admit I was thinking about a more general purpose method to increment/decrement by any amount.