delete an element from an array in classic ASP

Question

Given the following array as an example...

arr(0)(0) = 3
arr(0)(1) = name
arr(0)(2) = address
arr(1)(0) = 7
arr(1)(1) = name
arr(1)(2) = address
arr(2)(0) = 14
arr(2)(1) = name
arr(2)(2) = address

I need to delete the middle element (id=7) from the array. I understand that I need to loop through the array and move each record that isnt to be deleted into a new array. I tried like this...

Dim newArr,i
Redim newArr(Ubound(arr))

For i = 0 to Ubound(arr)
    If (CStr(arr(i)(0)) <> 7 ) Then
        newArr(i) = arr(i)
    End if
Next

When debugging this I can see the if statement work so I know only 2 elements are copied but newArr is empty at the end of this. What am I missing. I am a PHP coder that is new to classic asp and Im used to having array functions that make this kind of thing unnecessary. Any help appreciated. Thank you.

I am aware of scripting.dictionary, however, the array in question is used throughout a very large site and I do not have access to alter it at this point. — alan shaw, Jul 19 '13 at 19:11
Not really a solution but: this is not an asp-problem. ASP is just a container for the scripting language, in your case VBscript. Your problem is therefore a VBscript problem. This knowledge may help you search google more successfully. — Jeff, Jul 19 '13 at 20:30

score 7 · Answer 1 · answered Jul 19 '13 at 18:58

7

Instead of using array you can give Scripting.Dictionary a try.

It is much more flexible, and has, among others Remove method.

answered Jul 19 '13 at 18:58

Yuriy Galanter

38,833
15
69
136

Unfortunately I dont have access to the creation of the array. It is a very large site and the array in question is used throughout. Not possible at this point to get away from it. – alan shaw Jul 19 '13 at 19:09

score 7 · Accepted Answer · answered Jul 21 '13 at 11:11

You don't need new array, you can just reassign the items and "crop" the array:

Const removalIndex = 1
For x=removalIndex To UBound(arr)-1
    arr(x) = arr(x + 1)
Next
ReDim Preserve arr(UBound(arr) - 1)

This code will remove the array item at index 1 from the main array. If you don't know in advance the index of the item to remove, you can easily find it with a simple loop over the array.

score 5 · Answer 3 · edited May 23 '17 at 12:07

5

I suggest using Scripting.Dictionary and using it as a List/collection instead, as it allows for insertions and deletions. See here: Lists in VBScript

edited May 23 '17 at 12:07

Community

1
1

answered Jul 19 '13 at 18:58

Dai

141,631
28
261
374

score 0 · Answer 4 · answered Jul 19 '13 at 20:50

I don't know the definitive answer, but if I were to take a stab in the dark guess I'd suggest that since the array is two dimensional maybe you have to explicitly refer to it that way?

Dim newArr,i
Redim newArr(Ubound(arr),3)

For i = 0 to Ubound(arr)
    If (CStr(arr(i)(0)) <> 7 ) Then
        newArr(i)(0) = arr(i)(0)
        newArr(i)(1) = arr(i)(1)
        newArr(i)(2) = arr(i)(2)
    End if
Next

score 0 · Answer 5 · answered Jul 21 '13 at 03:12

I see some VBScript syntax issues. First:

arr(0)(0) = 3  'ERROR: Subscript out of range
arr(0, 0) = 3  'CORRECT

ReDim newArr(Ubound(arr))  'this is 1 dimensional array
newArr(0) = arr(0)         'this will NOT work
newArr(0) = arr(0, 0)      'this will work

And finally: why you convert to String and then compare it to an Integer with:

(CStr(arr(i)(0)) <> 7)

delete an element from an array in classic ASP

5 Answers5