Linking columns until new values in column A - excel

Question

In the attached table I would like to link cell contents via VBA.
Column A contains contents that should be linked to the cells in column B until a new content is added to A.
The example in the attached table is shortened. The tables are much longer.
I have made a 'before' and an 'after' sheet.
The code I have is linked from A to B until a new value comes into A. But the VBA always takes the newest value in column B and not all the previous ones.
How can I adjust the code so that all values from B are linked to A until a new value comes into column A?
Sub Linking_columns_until_new_values()
Dim arr
Dim z As Long
Dim txt As String
Dim ws As Worksheet
For Each ws In Worksheets
ws.Select
With ActiveSheet.UsedRange.Columns(1).Resize(, 2)
.Columns(1).SpecialCells(xlCellTypeBlanks).Font.Bold = False
arr = .Value
For z = 1 To UBound(arr)
If arr(z, 1) <> "" Then
txt = arr(z, 1)
ElseIf arr(z, 2) = "" Then
arr(z, 1) = ""
Else
arr(z, 1) = txt & " " & arr(z, 2)
End If
Next
.Value = arr
End With
Next
End Sub
Here is the link to the sheet:
https://www.evernote.com/l/AGApoCGk-OJGKaHxwB2F-VCjO9uWJN299TM/

Answer 1

There is no need to use VBA for this:
In B1, because it's first entry, I copied manually.
My formula in B2 is =IF(B2="";"";C1&B2) and drag down
My formula in C1 is =B1 and drag down
Later on you could copy/paste formats, paste values, and then delete columns A and B. That way you would get what you got in After Sheet
Probably you can use the macro recorder to get the code and adapt it to your needs if you need VBA solution.
Hope this helps