How do you make VBA run on multiple cells? - excel

Question

I am very new to VBA but pretty good at formulas. I am working on a time stamp issue. I have the code written so that if I choose from a validation list in E3 it will give me a time stamp in F3. I want this to be true of all cells in the E column starting with E3. I will have between 500 and 15000 records (rows). The code I am using is pasted below. Thanks in advance for any suggestions.
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column = 5 And Target.Row = 3 Then
If Target.Value = "" Then
Cells(3, 6).Value = ""
Else
Cells(3, 6).Value = Format(Now, "mm/dd/yyyy HH:mm:ss")
End If
End If
End Sub

Answer 1

How's this?
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column = 5 And Target.Row >= 3 Then
i = Target.Row
If Target.Value = "" Then
Cells(i, 6).Value = ""
Else
Cells(i, 6).Value = Format(Now, "mm/dd/yyyy HH:mm:ss")
End If
End If
End Sub

Answer 2

The fastest way to do this is to select the entire range a set the value once using an array. This is done with the .Value property of a Range when it contains multiple cells.
Private Sub SetDate(ByVal Target As Range, Optional bybal RowCount as Long = 0)
Dim i as Long
' Check if row count needs to be found
If RowCount = 0 Then
'Count non-empty rows from target down
RowCount = Target.Worksheet.Range(Target, Target.End(xlDown).Rows.Count
End If
' Target entire range of cells that are going to be affected
Set Target = Target.Resize(RowCount, 6)
Dim vals() as Variant
' Read values from worksheet
vals = Target.Values
' Make changes in memory here
For i=1 to RowCount
if IsEmpty(vals(i,1)) Then
vals(i, 6) = vbNullString
Else
vals(i, 6) = Format(Now, "mm/dd/yyyy HH:mm:ss")
End If
Next i
' Write values into worksheet
Target.Value = vals
End Sub