Excel VBA function returning an array - vba

Question

Can you create an Excel VBA function that returns an array in the same manner as LINEST does, for example? I would to create one that, given a supplier code, returns a list of products for that supplier from a product-supplier table.

Answer 1

ok, here I have a function datamapping that returns an array of multiple 'columns', so you can shrink this down just to one.
Doesn't really matter how the array gets populated, particularly
Function dataMapping(inMapSheet As String) As String()
Dim mapping() As String
Dim lastMapRowNum As Integer
lastMapRowNum = ActiveWorkbook.Worksheets(inMapSheet).Cells.SpecialCells(xlCellTypeLastCell).Row
ReDim mapping(lastMapRowNum, 3) As String
For i = 1 To lastMapRowNum
If ActiveWorkbook.Worksheets(inMapSheet).Cells(i, 1).Value <> "" Then
mapping(i, 1) = ActiveWorkbook.Worksheets(inMapSheet).Cells(i, 1).Value
mapping(i, 2) = ActiveWorkbook.Worksheets(inMapSheet).Cells(i, 2).Value
mapping(i, 3) = ActiveWorkbook.Worksheets(inMapSheet).Cells(i, 3).Value
End If
Next i
dataMapping = mapping
End Function
Sub mysub()
Dim myMapping() As String
Dim m As Integer
myMapping = dataMapping(inDataMap)
For m = 1 To UBound(myMapping)
' do some stuff
Next m
end sub

Answer 2

I think Collection might be what you are looking for.
Example:
Private Function getProducts(ByVal supplier As String) As Collection
Dim getProducts_ As New Collection
If supplier = "ACME" Then
getProducts_.Add ("Anvil")
getProducts_.Add ("Earthquake Pills")
getProducts_.Add ("Dehydrated Boulders")
getProducts_.Add ("Disintegrating Pistol")
End If
Set getProducts = getProducts_
Set getProducts_ = Nothing
End Function
Private Sub fillProducts()
Dim products As Collection
Set products = getProducts("ACME")
For i = 1 To products.Count
Sheets(1).Cells(i, 1).Value = products(i)
Next i
End Sub
Edit:
Here is a pretty simple solution to the Problem: Populating a ComboBox for Products whenever the ComboBox for Suppliers changes it's value with as little vba as possible.
Public Function getProducts(ByVal supplier As String) As Collection
Dim getProducts_ As New Collection
Dim numRows As Long
Dim colProduct As Integer
Dim colSupplier As Integer
colProduct = 1
colSupplier = 2
numRows = Sheets(1).Cells(1, colProduct).CurrentRegion.Rows.Count
For Each Row In Sheets(1).Range(Sheets(1).Cells(1, colProduct), Sheets(1).Cells(numRows, colSupplier)).Rows
If supplier = Row.Cells(1, colSupplier) Then
getProducts_.Add (Row.Cells(1, colProduct))
End If
Next Row
Set getProducts = getProducts_
Set getProducts_ = Nothing
End Function
Private Sub comboSupplier_Change()
comboProducts.Clear
For Each Product In getProducts(comboSupplier)
comboProducts.AddItem (Product)
Next Product
End Sub
Notes: I named the ComboBox for Suppliers comboSupplier and the one for Products comboProducts.