Interesting Array Warnings

[FinalVersion]

#include <File.au3>

Local $String, $Array, $Max

$String = FileReadLine(@ScriptDir & "\Data.txt", 1)
$Array = StringSplit($String, ".")
$Max = UBound($Array)

For $i = 1 To $Max Step +1
    MsgBox(0, "", $Array[$i])
Next

So i spotted this in the console

C:\Users\Scott\Documents\AutoIt\Arrays\Hmm.au3 (10) : ==> Array variable has incorrect number of subscripts or subscript dimension range exceeded.:
MsgBox(0, "", $Array[$i])
MsgBox(0, "", ^ ERROR

Obviously it's not the end of the world, the script still runs fine, just curious about this.

[Melba23]

Finalversion,

Ah, this old chestnut again!

Arrays in AutoIt start at element [0], so a 5 element array has [0], [1], [2], [3], [4]

UBound, on the other hand, gives you the total number of elements, a 5 element array will return 5.

Can you see where this is going yet?

You have set your For...Next loop as 1 To $Max - when it should be 0 To $Max - 1.

I know your first reaction will be: "Why the hell does UBound return 5!" - you are not alone! However, you are warned - from the Help file for UBound: "Remember that the value returned by UBound is one greater than the index of an array's last element!". Personally I would have called UBound something else, like NumElements, but then I did not write it. If it is any consolation, I still have to think very carefully about the upper and lower limits of array elements and often get my For...Next counter wrong on the first pass.

You might find this topic of interest if you want to see a bit more confusion......

M23

[FinalVersion]

Yeah I remember reading that, so should this work?

For $i = 1 to $Max -1 Step +1

[omikron48]

For $i = 0 to $Max -1

You skipped the [0] element, not unless that was intentional.

Also, You don't need to specify the step as being +1. It is +1 by default. You only use Step when you need a different Step value.

[enaiman]

Yeah I remember reading that, so should this work?

Would you like someone else to test the script for you?? ... by the way - with icecream on top or without?

[FinalVersion]

Ok it's cleared up.