for..next and do...loop confusion

[SilentScreamer]

I have posted two bits of code below, they both pause for 10,000ms but the do...loop option is 1 byte smaller. Is there any advantage to using for..next over do...loop other than it is a little less to type?

for b0 = 0 to 100
	pause 10
	next

do
	inc b0
	pause 10
	loop until b0 = 100

EDIT: Before anyone says anything I know pause 10000 works, I did this as a test to see if for...next used less space.

 

[Dippy]

Dunno.

You've got a nice choice which to use.

There are many advantages of the Do/Loop structure over For/Next.
1. You have more control over conditionals.
2. Generally safer (in many laguages, not sure about PICAXE) for a premature loop exit.
3. Test the conditional before the loop or after.
4. The conditional needn't be the loop variable.
5. Variable increments for loop variable.

There maybe more , but my kettle is boiling.

 

[Texy]

You say its '1 byte smaller', but you haven't initialised b0 at the beginning,
or did you take that into account?

Texy

 

[SilentScreamer]

Thanks for the post Dippy, I hadn't thought about those advantages.

Also a very good point Texy, I didn't need to with it being at the top of a program. Adding "b0 = 0" adds a further 3 bytes removing the entire point. I think that solves it.

 

[hippy]

The general case equivalence of -

For var = first To last Step +/- step
Next

is

var = first
Do
var = var +/- step
Loop Until var < first Or var > last

And the FOR-NEXT will be shorter than DO-LOOP. However, where you can drop parts of that out, you can use DO-LOOP to achieve shorter code. The FOR-NEXT is (AFAIR) slightly faster to execute.