Assigning a local array with 0 elements

[SlowCoder74]

Hey all. Strange happenings here. Hoping you can help.

Here's my very simple test code:

$retVal = MyFunc()
Func MyFunc()
    local $MyArr[0]
EndFunc

If I try to assign my local array with 0 elements, does it return "Array variable subscript badly formatted"? If I assign simply change it to $MyArr[1], it works without errors. I've even tried to assign it with 1 element, then redim it to 0 elements, and it still chokes at the redim statement. I need my array to start at 0.

[somdcomputerguy]

The index# of the first element starts at 0, and AFAIK, an array has to have at least one element, or else it's just a variable.

[SlowCoder74]

Sorry, got my terms mixed up. I should have said "index" instead of "elements", because index 0 is the first element. It's getting late.

I've never run into a language, apparently until now, that didn't allow an array to be dimensioned with a ubound of 0. That still allows for 1 element at index 0. Am I missing something here with AutoIT?

[Skitty]

Hey all. Strange happenings here. Hoping you can help.

Here's my very simple test code:

$retVal = MyFunc()
Func MyFunc()
    local $MyArr[0]
EndFunc

If I try to assign my local array with 0 elements, does it return "Array variable subscript badly formatted"? If I assign simply change it to $MyArr[1], it works without errors. I've even tried to assign it with 1 element, then redim it to 0 elements, and it still chokes at the redim statement. I need my array to start at 0.

Just curious.

Why?

[SlowCoder74]

Just curious.

Why?

I'm not sure what you're referring to, but I'm guessing you're talking about the "0 elements", which I updated to mean "an index of 0" in post #3.

[Skitty]

I'm not sure what you're referring to, but I'm guessing you're talking about the "0 elements", which I updated to mean "an index of 0" in post #3.

I know.

I mean I'm just curious of what use this would have.

[BrewManNH]

Just hang on until the next beta release, this will probably be implemented.

[jchd]

I've only been recently aware that AutoIt can manipulate empty arrays (arrays with no elements) and current AutoIt doesn't have any problem with them.

It's just that you can't create them directly: they have to be the result of an external operation.

Anyway and beyond this technicality, empty arrays are no panacea to programming and lack of them is no barrier to having things done.

[guinness]

Implemented in the Alpha release of AutoIt >>

[jchd]

Seems like the horse is out of the barn sooner than I thought. Note that this is alpha explosive, so handle with care and no smoking around...

[AdmiralAlkex]

For 1 element then write

local $MyArr[1]

[ProgAndy]

If you need a one dimensional array with 0 elements in the current version, you can go through an object:

Func _ArrayGetEmpty()
    Local Static $array
    If IsArray($array) Return $array
    Local $o = ObjCreate("Scripting.Dictionary")
    $array = $o.Keys()
    Return $array
EndFunc

Edited April 18, 2012 by ProgAndy

[AdmiralAlkex]

Guys guys, he said he wanted 1 element. First element is in 0 but array creation is 1 based, hence what I posted.

[guinness]

Guys guys, he said he wanted 1 element. First element is in 0 but array creation is 1 based, hence what I posted.

Local $aArray[1] = [0] ; Shouldn't it be this then?

[AdmiralAlkex]

Local $aArray[1] = [0] ; Shouldn't it be this then?

I don't know what that is supposed to be.

[Malkey]

I don't know what that is supposed to be.

@AdmiralAlkex

With a positive approach, guinness's script is obvious "what that is supposed to be". It is the same script as your posted script, post #11, together with assigning a value, "0" - a zero-based value, similar to its index.

This might help.

Local $aArray[1] = [0]
ConsoleWrite("$aArray[0] = " & $aArray[0] & @LF) ; This (one element) array has a zero-based index.
;Returns:-
;$aArray[0] = 0

Here is an example for ProgAndy's "_ArrayGetEmpty" function relating to the threads title and to pre-post #3 - before SlowCoder74 have up on "Local $array[0]" and "ReDim $array[0]".

Local $a = _ArrayGetEmpty() ; Creates an empty array (no elements).
; ConsoleWrite($a[0] & @LF) ; <-- Create error. This one dimensional array has no elements, thus, no index - a nothing-based index.
MsgBox(0, "Empty array", _
        "IsArray(): "   & IsArray($a) & @LF & _
        "No.rows: "  & UBound($a) & @LF & _
        "No.columns: "  & UBound($a, 2) & @LF & _
        "No. of dims: " & UBound($a, 0))

ReDim $a[UBound($a) + 1] ; $a has to be an array variable for ReDim to work correctly.
MsgBox(0, "Empty array", _
        "IsArray(): "   & IsArray($a) & @LF & _
        "No.rows: "  & UBound($a) & @LF & _
        "No.columns: "  & UBound($a, 2) & @LF & _
        "No. of dims: " & UBound($a, 0))


; http://www.autoitscript.com/forum/topic/139665-assigning-a-local-array-with-0-elements/page__view__findpost__p__980047
Func _ArrayGetEmpty()
    Local Static $array
    If IsArray($array) Then Return $array ; <-- "Then" Added
    Local $o = ObjCreate("Scripting.Dictionary")
    $array = $o.Keys()
    Return $array
EndFunc   ;==>_ArrayGetEmpty

[UEZ]

My glass ball shows me that one of the next AutoIt releases will have empty array feature...

-> Dim $array[0]

Br,

UEZ

Edited April 20, 2012 by UEZ

[ProgAndy]

My glass ball shows me that one of the next AutoIt releases will have empty array feature...

Thats why I wrote "in the current autoit release"

[AdmiralAlkex]

@Malkey

Yeah but I don't see where anyone said anything about any value.

@SlowCoder74

Why don't you stop trolling and confirm something before we all go mad!

[SlowCoder74]

Guys guys, he said he wanted 1 element. First element is in 0 but array creation is 1 based, hence what I posted.

Yes, this is exactly what I'm saying. 0-based array, but AutoIT doesn't seem to (currently) support it. Typically data can be stored at [0] in other languages. If this is not doable at this time, I'm sure I can find a way around it.

@SlowCoder74 Why don't you stop trolling and confirm something before we all go mad!

LOL! I just got back here to read all of your responses.