Reversing a list in Excel within a formula

Question

So there are a bunch of ways to reverse a list to turn it into a new list, using helper columns. I\'ve written some code that does use helper columns to reverse a list and t

Answer 1

Actually you can make the formula in your Question work (with a small UDF()):

Pick a cell and enter:

=SUMPRODUCT(reverse(A1:A3),B1:B3)

with this in a standard module:

Public Function reverse(rng As Range)
    Dim ary(), N As Long, i As Long
    N = rng.Count
    ReDim ary(1 To N)
    i = N

    For Each r In rng
        ary(i) = r.Value
        i = i - 1
    Next r

    With Application.WorksheetFunction
        reverse = .Transpose(ary)
    End With
End Function