VBA return dynamic array and assign to variable - excel

Question

Return dynamic array from function VBA got me part of the way on this problem. I realized I should know size prior to invoking the function.
Function GetHeadersFromRange(DataRange As Range, Size As Integer) As Variant
Dim Column As Integer
Dim Headers As Variant
ReDim Headers(0 To Size)
For Column = 1 To DataRange.Columns.Count
Headers(Column) = DataRange(1, Column).Value
Next
GetHeadersFromRange = Headers
End Function
Sub TestGetHeadersFromRange()
Application.DisplayAlerts = False
Set wb = ThisWorkbook
Set TestSheet = wb.Sheets.Add()
TestSheet.Range("A1").Value = "my_header"
TestSheet.Range("A2").Value = "val"
Dim DataRange As Range: Set DataRange = TestSheet.Range("A1:A2")
Dim Size As Integer: Size = DataRange.Columns.Count
Dim Result As Variant
' Gets type mismatch
Set Result = GetHeadersFromRange(DataRange, Size)
End Sub
Not entirely sure what to do here. I need to use this function in multiple places which is why it is a function in the first place.
Edit: Clarify problem
Set Result = GetHeadersFromRange(...) gets a type mismatch.

Answer 1

Header Function
Improvement
Your error occurs because you are using Set (used for objects)
on an array.
A more efficient (faster) way than looping through a range is looping
through an array.
When you copy a range to a variant (possibly array), if the range
contains one cell, the variant will contain one value only. But if
the range contains multiple cells, it will be an array, whose size is
returned with UBound. Therefore there is no need for a Size argument.
IsArray is used to determine if a variant is an array. In our case we can check if the number of columns (elements) is greater than 1 instead.
Option Explicit
Function GetHeadersFromRange(DataRange As Range) As Variant
Dim vntR As Variant ' Range Variant
Dim vntH As Variant ' Header Array
Dim Noe As Long ' Number of Elements
Dim j As Long ' Range Array Column Counter,
' Header Array Element Counter
With DataRange
' Calculate Number of Elements.
Noe = .Columns.Count
' Calculate Header Range.
' Copy Header Range to Range Variant.
vntR = .Resize(1, Noe)
' Note: Range Variant (vntR) is a 2D 1-based 1-row array only if
' DataRange contains more than one column. Otherwise it is
' a variant containing one value.
End With
'' Check if Range Variant is an array.
'If IsArray(vntR) Then
' Check if Number of Elements is greater than 1.
If Noe > 1 Then
' Resize 1D 0-based Header Array to number of columns (2) in Range
' Array minus 1 (0-based).
ReDim vntH(Noe - 1)
' Loop through columns of Range Array.
For j = 1 To Noe
' Write value at first row (1) and current column (j) of Range
' Array to current element (j-1) of Header Array.
vntH(j - 1) = vntR(1, j)
Next
Else
' Resize 1D 0-based Header Array to one element only (0).
ReDim vntH(0)
' Write Range Variant value to only element of Header Array.
vntH(0) = vntR
End If
GetHeadersFromRange = vntH
End Function
Sub TestGetHeadersFromRange()
Dim TestSheet As Worksheet ' Source Worksheet
Dim DataRange As Range ' Data Range
Dim Result As Variant ' Result Variant (possibly Array)
Dim i As Long ' Result Array Element Counter
' Add a new worksheet (Source Worksheet).
' Create a reference to the newly added Source Worksheet.
Set TestSheet = ThisWorkbook.Sheets.Add()
' In Source Worksheet
With TestSheet
' Add some values.
.Range("A1").Value = "my_header"
.Range("A2").Value = "val"
.Range("B1").Value = "my_header2"
.Range("B2").Value = "val2"
End With
' Test 1:
Debug.Print "Test1:"
' Create a reference to DataRange.
Set DataRange = TestSheet.Range("A1:A2")
' Write Data Range to 1D 0-based Result Array.
Result = GetHeadersFromRange(DataRange)
' Loop through elements of Result Array.
For i = 0 To UBound(Result)
' Write current element of Result Array to Immediate window.
Debug.Print Result(i)
Next
' Test 2:
Debug.Print "Test2:"
' Create a reference to DataRange.
Set DataRange = TestSheet.Range("A1:B2")
' Write Data Range to 1D 0-based Result Variant.
Result = GetHeadersFromRange(DataRange)
' Loop through elements of Result Array.
For i = 0 To UBound(Result)
' Write current element of Result Array to Immediate window.
Debug.Print Result(i)
Next
End Sub