Single column values ends up in multi dimension array - excel

Question

I am populating a array with values from part of a column (range). The resulting array is multidimensional - but it should be one dimensional. I want to get just Emp ID values into the array:
I have tried this :
Sub Test()
Dim colPostionNumber As Integer
Dim lastRow As Integer
Dim ws As Worksheet
Dim positionNumberArray As Variant
Set ws = ActiveSheet
With ActiveWorkbook.Sheets("Sheet 1")
colPositionNumber = Application.WorksheetFunction.Match("Emp ID", ws.Rows(5), 0)
lastRow = ws.UsedRange.SpecialCells(xlCellTypeLastCell).row
positionNumberArray = .Range(Cells(5, colPositionNumber), Cells(lastRow, colPositionNumber)).Value
End With
End Sub
But the resulting array is two dimensional
I tried reDim but that didn't work. How do I do this with a one dimensional array?

Answer 1

Write One-Column 2D Array to 1D Array
To get a zero-based 1D array, you will have to loop.
Sub Test()
Dim colPositionNumber As Long
Dim lastRow As Long
Dim ws As Worksheet
Dim Data As Variant
Dim positionNumberArray As Variant
Set ws = ActiveSheet
With ActiveWorkbook.Sheets("Sheet 1")
colPositionNumber = Application.Match("Emp ID", ws.Rows(5), 0)
lastRow = ws.UsedRange.SpecialCells(xlCellTypeLastCell).Row
Data = .Range(.Cells(5, colPositionNumber), _
.Cells(lastRow, colPositionNumber)).Value
ReDim positionNumberArray(UBound(Data, 1) - 1)
Dim n As Long
For n = 1 To UBound(Data, 1)
positionNumberArray(n - 1) = Data(n, 1)
Next n
End With
End Sub
Using Application.Transpose
The following procedures show how to write a one-column or a one-row range to a one-based 1D array:
Sub testATColumn()
Dim rg As Range: Set rg = Range("A1:A5")
Dim arr As Variant: arr = Application.Transpose(rg.Value)
Debug.Print LBound(arr, 1), UBound(arr, 1)
On Error Resume Next
Debug.Print LBound(arr, 2), UBound(arr, 2)
On Error GoTo 0
End Sub
Sub testATRow()
Dim rg As Range: Set rg = Range("A1:E1")
Dim arr As Variant
arr = Application.Transpose(Application.Transpose(rg.Value))
Debug.Print LBound(arr, 1), UBound(arr, 1)
On Error Resume Next
Debug.Print LBound(arr, 2), UBound(arr, 2)
On Error GoTo 0
End Sub
Note that Application.Transpose has a limit of 65535 elements per dimension.

Answer 2

Reduce dimension via Excel function ArrayToText()
If you dispose of version MS 365 you could try the following approach via Excel function ArrayToText() and an eventual split action.
Sub reduceDim()
Dim t#: t = Timer
Dim rng As Range
Set rng = Sheet1.Range("B2:B7") ' << change to your needs
Dim data
data = Split(Evaluate("ArrayToText(" & rng.Address(False, False, External:=True) & ")"), ", ")
Debug.Print "Array(" & LBound(data) & " To " & UBound(data) & ")"
Debug.Print Join(data, "|") ' display resulting 0-based 1-dim array elements
Debug.Print Format(Timer - t, "0.00 secs")
End Sub
Output in VB Editor's immediate window
Array(0 To 5)
1|2|3|4|5|6
0,00 secs