If_function_vba

Sub FillFinalRatings()
    Dim ws As Worksheet
    Dim lastRow As Long
    Dim i As Long

    Set ws = ThisWorkbook.Sheets("Sheet1")

    lastRow = ws.Cells(ws.Rows.Count, "J").End(xlUp).Row

    For i = 2 To lastRow
        If ws.Cells(i, "J").Value = "0" Then
            ws.Cells(i, "AB").Value = ws.Cells(i, "O").Value
        Else
            ws.Cells(i, "AB").Value = "D"
        End If
    Next i

End Sub