Create dictionary of lists in vba

Question

I have worked in Python earlier where it is really smooth to have a dictionary of lists (i.e. one key corresponds to a list of stuff). I am struggling to achieve the same in

Answer 1

I am not that familiar with C++ and Python (been a long time) so I can't really speak to the differences with VBA, but I can say that working with Arrays in VBA is not especially complicated.

In my own humble opinion, the best way to work with dynamic arrays in VBA is to Dimension it to a large number, and shrink it when you are done adding elements to it. Indeed, Redim Preserve, where you redimension the array while saving the values, has a HUGE performance cost. You should NEVER use Redim Preserve inside a loop, the execution would be painfully slow

Adapt the following piece of code, given as an example:

Sub CreateArrays()

Dim wS As Worksheet
Set wS = ActiveSheet

Dim Flanged_connections()
ReDim Flanged_connections(WorksheetFunction.CountIf(wS.Columns(1), _
    "Flanged_connections"))

For i = 1 To wS.Cells(1, 1).CurrentRegion.Rows.Count Step 1

    If UCase(wS.Cells(i, 1).Value) = "FLANGED_CONNECTIONS" Then   ' UCASE = Capitalize everything

        Flanged_connections(c1) = wS.Cells(i, 2).Value

    End If

Next i

End Sub