For...Next Step Variable

BackupUser · **Joined:** Tue Apr 22, 2003 7:42 pm **Posts:** 16777133

Restored from previous forum. Originally posted by ebs.

Fred,

I don't know if this was requested before, but please make the Step value in a For...Next loop a *variable*, not a constant. I often want to set the step based on other variables, and also be able to "reverse direction" in the loop by using: "StepValue = -StepValue".

Regards,
Eric

BackupUser · **Joined:** Tue Apr 22, 2003 7:42 pm **Posts:** 16777133

Restored from previous forum. Originally posted by VPureBasic.

Hi ebs,

Why you did not try something like...

For x = A to B step C
...
...
Next x

A = ( your start )
B = ( your limit )
C = ( your step value )

Roger

BackupUser · **Joined:** Tue Apr 22, 2003 7:42 pm **Posts:** 16777133

Restored from previous forum. Originally posted by PB.

> Why you did not try something like...
> For x = A to B step C

Doesn't work. Compiler complains about C not being a constant.

BackupUser · **Joined:** Tue Apr 22, 2003 7:42 pm **Posts:** 16777133

Restored from previous forum. Originally posted by tinman.

Quote:

Originally posted by ebs

I don't know if this was requested before, but please make the Step value in a For...Next loop a *variable*, not a constant. I often want

Better making it an expression (so you can do e.g. "... Step foo+bar(blah)"

--
It's not minimalist - I'm increasing efficiency by reducing input effort.
(Win98first ed. + all updates, PB3.50)

BackupUser · **Joined:** Tue Apr 22, 2003 7:42 pm **Posts:** 16777133

Restored from previous forum. Originally posted by Kendrel.

actually it works if the step variable is a constant or a fixed number... but it would be nice if one could also use a variable.

my 2 cents

kendrel

BackupUser · **Joined:** Tue Apr 22, 2003 7:42 pm **Posts:** 16777133

Restored from previous forum. Originally posted by fred.

I take good notes.

Fred - AlphaSND

Master Games · **Joined:** Mon Oct 06, 2003 1:42 am **Posts:** 22

Fred, is this feature in the next version? or can it still be added if it is not?

Fred · **Posted:** Tue Nov 18, 2003 6:35 pm

Not implemented for now...

GPI · **Joined:** Fri Apr 25, 2003 6:41 pm **Posts:** 1364

Fred wrote:

Not implemented for now...

But would be a good idea (and i can't imagine, that it is a big problem)

Master Games · **Joined:** Mon Oct 06, 2003 1:42 am **Posts:** 22

GPI wrote:

Fred wrote:

Not implemented for now...

But would be a good idea (and i can't imagine, that it is a big problem)

I second that! Since C allows you to do it.

PB · **Joined:** Fri Apr 25, 2003 5:24 pm **Posts:** 7581

Until Fred implements 'Step' as a variable, you can always do it like this:

Code:

; Example of 'For a=1 To 40 Step b' in PureBasic,
; because you can't use variables for 'Step' yet.

b=2 ; The 'Step' value (normally a constant!).
For a=1 To 40
  Debug a ; Do whatever processing on 'a' here.
  a+b-1   ; This MUST go directly before 'Next'!
Next

blueznl · **Joined:** Sat May 17, 2003 11:31 am **Posts:** 6074

oh, pb, use repeat until or while wend instead! brrr...

; for a = 1 to 40 step b

a = 1
while a+b <= 40
; whatever
a = a+b
wend

or

a=1
repeat
; whatever
a = a+b
until a > 40

PB · **Joined:** Fri Apr 25, 2003 5:24 pm **Posts:** 7581

> use repeat until or while wend instead

But then it's not a For/Next loop with a variable anymore, is it? :lol:

dontmailme · **Joined:** Wed Oct 29, 2003 10:35 am **Posts:** 537

For - Next works well as it is
While - Wend and repeat - until can do the step.....

Everythings quick !

Why change a winning formula ?

This isn't TrueBasic, or a TRUE Basic, it's a very fast basic !

Why do we need the variable step, if it will slow the loop down ?

Froggerprogger · **Joined:** Fri Apr 25, 2003 5:22 pm **Posts:** 423

Of course the compiler could&should watch for the step-parameter if it is a const or a variable and then compile to the fast loop as always if it is a const or to another loop if it is a variable...

Anyway, I personally don't need step-variables, it would only be a nice gimmick.

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