Add single value to a multidimensional array vba and then redim

Question

I am running into some issues trying to populate a multidimensional variant array. What I am trying to do is add a single value to row 1, column 1 in the array. However the following code does not work.

Dim arr() As Variant
arr(1,1) = 3

Building on this, I am wishing to add more values to the array when certain conditions are met. eg

 For c = 2 To 10001
        Sheets("Data").Select
        If Range("P" & c) = branch And Range("Q" & c) = dept And Range("R" & c) = subdept Then
            arr(UBound(arr) + 1, 1) = Range("A" & c)
        End If
    Next c

After the loop has finished and I have finished extracting the values I am after I wish to redim it as a variable length array. However,

Redim arr()

also is not working. Also, I should point out that I have no real need for the array to be multidimensional, just variable in size. Saying that, I do not know of a way to create a 1 dimensional dynamic array in VBA.

To summarize

1) Why does arr(1,1) throw me an error?

2) Why does Redim arr() throw me an error? (I do not want to redim to a fixed size)

3) Is there a way to create a dynamic 1D array in VBA?

Note: I suppose I could declare a 1D 100 length array which I could then manipulate to work out the number of filled values in it and redim it as (0 to 100), but first wish to explore if there are any answers to my above questions.

Many thanks.

UPDATE: (my second attempt: still fails on arr(arrLen, 1) = Range("A" & c))

 arrLen = 1

    For c = 2 To 10001
        Sheets("Data").Select
        If Range("P" & c) = branch And Range("Q" & c) = dept And Range("R" & c) = subdept Then
            ReDim Preserve arr(arrLen To 1)
            arr(arrLen, 1) = Range("A" & c)
            arrLen = arrLen + 1
        End If
    Next c

Answer 1

Working code below.

Option Base 1

Dim arr() as string
    arrLen = 1

    For c = 2 To 10001
        Sheets("Data").Select
        If Range("P" & c) = branch And Range("Q" & c) = dept And Range("R" & c) = subdept Then
            ReDim Preserve arr(1 To arrLen)
            arr(arrLen) = Range("A" & c)
            arrLen = arrLen + 1
        End If
    Next c

Answer 2

Two reasons.

• Your array has only 1 dimension, not two
• Your logic should be 1 To arrLen not arrLen to 1

recut

ReDim Preserve arr(1 To arrLen)
arr(arrLen) = Range("A" & c)
arrLen = arrLen + 1

Answer 3

Because you are dealing with a fixed range (cells 2 to 10001) -- or even a dynamic range, really -- you can avoid putting ReDim inside your loop.

ReDim arr(1 to 10001)
For c = 2 To 10001
    Sheets("Data").Select
    If Range("P" & c) = branch And Range("Q" & c) = dept And Range("R" & c) = subdept Then
        arr(arrLen) = Range("A" & c)
        arrLen = arrLen + 1
    End If
Next c
ReDim Preserve arr(1 to arrLen)

That should speed up your performance. So first you are making the array as big as it could ever need to be, given the known iteration of your For loop. Then you process your data, putting it in to the array, and after the loop terminates, you ReDim it back down to get rid of the empty elements.