VBA For loop where number of iterations can be changed from inside loop

**barrboy89** · 05-11-2011, 11:20 AM

Hi Guys,

I have some code that is like this:

For i = 1 To Num
If criteria
do some stuf
Num = Num + 1
End if
Next i

So basically, each time the condition is true, along with doing all the stuff, i also want it to run an extra time.

I though the above code would be fine, but say Num is originally 20, it will still only run to 20 even when Num now = 24 after being modified from within the loop.

Any clues as to how I could fix this?

Thanks in advance.

**davegugg** · 05-11-2011, 11:36 AM

Its hard to know without knowing what "do some stuff" does, but you could try:

1. Using a do until - loop instead of a for loop.
2. Instead of the line (or in addition to it) Num = Num + 1 use i = i-1.

**TMS** · 05-11-2011, 11:42 AM

Perhaps you could explain what it is you are trying to achieve

Regards

**barrboy89** · 05-11-2011, 11:53 AM

The Do Until thing worked, thanks a lot. Basically, if you change the x in "For i = 1 to x" from inside the loop it doesn't actually run the loop the new amount of times. But I did:
Do Until i = Num

i = i + 1
Loop

And this now works, I can increase Num within the loop and it will keep running until it reaches the increased Num, which the For loop wasn't able to do.

Thanks for your help.

**shg** · 05-11-2011, 12:18 PM

It's a cardinal sin of programming to change the loop counter inside a For/Next loop, and the loop limits are only evaluated once because they may be complex expressions. You're on the right track with a Do/Loop as Dave suggested.