Clear contents of cells when the cell left of it changes - vba

Question

I'm trying to get a piece of code that, when a cell in column 8 changes it deletes the value of cell next to it(column 9).
Well... That is the simple version
Column 8 and 9 are both dropdown lists, the dropdown list in column 9 is dependent on column 8. In column 9, multiple answers are necesary so i found a code on the internet that made that possible, but now the value in column 9 doesn't delete automatically when i change the value in column 8.
This piece of code below works, but only when i change 1 cell(in column 8) at the time. It doesn't work when i paste multiple Cells in Column 8 or when i select a cell in column 8 and then drag it down(from the lower right corner).
I don't have a lot of experience with coding and just can't seem to find the right solution for this.
Thanks to QHarr i got a bit further.
This is my second attempt:
Dim ClearC9 As String
Dim i As Long
For i = 2 To 1000
If Target.Cells.Count > 1 Then GoTo ClearC9
If Not Intersect(Target, Range("H" & i)) Is Nothing Then
Range("I" & i).ClearContents
End If
Next i
exitHandler:
Application.EnableEvents = True
Columns("I:I").EntireColumn.AutoFit
ClearC9:
Selection.Offset(, 1).ClearContents
First Attempt:
Dim i As Long
For i = 2 To 1000
If Target.Cells.Count > 1 Then Exit Sub
If Not Intersect(Target, Range("H" & i)) Is Nothing Then
Range("I" & i).ClearContents
End If
This is the entire code:
Private Sub Worksheet_Change(ByVal Target As Range)
Dim rngDV As Range
Dim oldVal As String
Dim newVal As String
Dim lUsed As Long
If Target.Count > 1 Then GoTo exitHandler
On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler
If rngDV Is Nothing Then GoTo exitHandler
If Intersect(Target, rngDV) Is Nothing Then
'do nothing
Else
Application.EnableEvents = False
newVal = Target.Value
Application.Undo
oldVal = Target.Value
Target.Value = newVal
If Target.Column = 9 Then
If oldVal = "" Then
'do nothing
Else
If newVal = "" Then
'do nothing
Else
lUsed = InStr(1, oldVal, newVal)
If lUsed > 0 Then
If Right(oldVal, Len(newVal)) = newVal Then
Target.Value = Left(oldVal, Len(oldVal) - Len(newVal) - 2)
Else
Target.Value = Replace(oldVal, newVal & ", ", "")
End If
Else
Target.Value = oldVal _
& ", " & newVal
End If
End If
End If
End If
End If
Dim i As Long
For i = 2 To 1000
If Target.Cells.Count > 1 Then Exit Sub
If Not Intersect(Target, Range("H" & i)) Is Nothing Then
Range("I" & i).ClearContents
End If
Next i
exitHandler:
Application.EnableEvents = True
Columns("I:I").EntireColumn.AutoFit
End Sub

Answer 1

The general pattern to to create an intersection range:
if it is Nothing then do nothing
otherwise loop over its cells
for example:
Private Sub Worksheet_Change(ByVal Target As Range)
Dim rngDV As Range, TheIntersection As Range, r As Range
' stuff
TheIntersection = Intersect(Target, rngDV)
If TheIntersection Is Nothing Then
' do nothing
Else
For Each r In TheIntersection
' do something
Next r
End If
End Sub