_ArrayDelete not updating array size on first use

[idbirch]

Hi all,

I'm trying to create a GUI application which lets users add and remove items from a list into a "basket". The GUI part works absolutely fine but the array in which I'm storing the final list of selected items is giving me a bit of grief. I'm using _ArrayAdd to add values and shockingly, _ArrayDelete to remove them. I need to be able to retrieve the number of items in the basket when the user clicks OK so I'm using _ArrayAdd and _ArrayDelete's return value to keep track of this and this is the problem:

Adding to the array is fine, the value increments by 1 with every item added. If I then remove an item from the list, the value is not reduced, it remains the same. If I remove another item, the value then goes down by 1 and continues to do so with every subsequent removal, problem is of course, the value is +1 what it should be. Anyone know why this happens?

I've written a very simple example which shows the problem:

expandcollapse popup

#include <ButtonConstants.au3>
#include <GUIConstantsEx.au3>
#include <ListBoxConstants.au3>
#include <WindowsConstants.au3>
#include <Array.au3>
#Include <GuiListBox.au3>


Global $Array[1]

Opt("GUIOnEventMode", 1)
#Region ### START Koda GUI section ### Form=
$Form1 = GUICreate("Form1", 229, 335, 193, 125)
$List1 = GUICtrlCreateList("", 16, 16, 193, 240)
$Button1 = GUICtrlCreateButton("Add", 32, 280, 51, 25, 0)
GUICtrlSetOnEvent(-1, '_Add')
$Button2 = GUICtrlCreateButton("Remove", 136, 280, 59, 25, 0)
GUICtrlSetOnEvent(-1, '_Remove')
GUISetState(@SW_SHOW)
GUISetOnEvent($GUI_EVENT_CLOSE, "_Close")
#EndRegion ### END Koda GUI section ###

While 1
    Sleep(100)
WEnd

Func _Add()
    $ValueToAdd = InputBox ( "Add to array", "Enter string to add to array", "" )
    GUICtrlSetData ( $List1, $ValueToAdd )
    $ArraySize = _ArrayAdd ( $Array, $ValueToAdd )
    MsgBox (0, "Debug", "Array size is now " & $ArraySize )
EndFunc

Func _Remove()
    $ValueToDelete = GuiCtrlRead ( $List1 )
    
    $index = _GUICtrlListBox_GetCaretIndex ($List1)
    _GUICtrlListBox_DeleteString ( $List1, $index )
    
    $ArraySize = _ArrayDelete ( $Array, $index )
    MsgBox (0, "Debug", "Array size is now " & $ArraySize )
    
EndFunc

Func _Close()
    Exit
EndFunc

[PsaltyDS]

Hi all,

I'm trying to create a GUI application which lets users add and remove items from a list into a "basket". The GUI part works absolutely fine but the array in which I'm storing the final list of selected items is giving me a bit of grief. I'm using _ArrayAdd to add values and shockingly, _ArrayDelete to remove them. I need to be able to retrieve the number of items in the basket when the user clicks OK so I'm using _ArrayAdd and _ArrayDelete's return value to keep track of this and this is the problem:

Adding to the array is fine, the value increments by 1 with every item added. If I then remove an item from the list, the value is not reduced, it remains the same. If I remove another item, the value then goes down by 1 and continues to do so with every subsequent removal, problem is of course, the value is +1 what it should be. Anyone know why this happens?

I've written a very simple example which shows the problem:

The two functions do not return the same thing.

The return value from _ArrayAdd() is the index of the added item, not the size of the array. Remember arrays are 0-based, so the index of the last item is one less than the size of the array, or count of total items.

The return value from _ArrayDelete() is the new size of the array, not the index of the new last item. So the last item's index after the delete is one less than that.

Demo:

#include <Array.au3>

Global $avArray[1] = [0]

For $n = 1 To 5
    $iRET = _ArrayAdd($avArray, $n)
    ConsoleWrite("Added, $iRET = " & $iRET & @LF)
Next
$avArray[0] = UBound($avArray) - 1

_ArrayDisplay($avArray, "$avArray")

For $n = 5 To 1 Step -1
    $iRET = _ArrayDelete($avArray, $n)
    ConsoleWrite("Deleted, $iRET = " & $iRET & @LF)
Next
$avArray[0] = UBound($avArray) - 1

_ArrayDisplay($avArray, "$avArray")

[idbirch]

Ah. Oops. Another case of RTFM properly. I don't know where I got the idea that _ArrayAdd returned the new size, sorry about that. But thank you for your help and the code example.