Dror has a worksheet that contains quite a bit of data. It is possible that the data in one column will be exactly the same as the data in another column, so he wonders if there is an easy way to delete any duplicate columns within the worksheet.
The first step, of course, is to figure out if two columns are identical or not. This can be determined rather easily with an array formula such as the following:
(Remember that an array formula is entered by using Shift+Ctrl+Enter.) The formula compares all the values in the first 100 rows of columns A and B. If they are all the same, then the formula returns TRUE. If any of the cells don’t match, then the formula returns FALSE. If the result is TRUE you could then delete one of the columns because they are the same.
If you want something that is a bit more automatic, meaning that the duplicate column is deleted, then you’ll need to use a macro. The following steps through all the columns in the worksheet and, starting with the right-most column, compares all the columns. If any are the same-regardless of their order in the worksheet-then the macro asks if you want the duplicate column deleted.
Sub DeleteDuplicateColumns() Dim rngData As Range Dim arr1, arr2 Dim i As Integer, j As Integer, n As Integer On Error Resume Next Set rngData = ActiveSheet.UsedRange If rngData Is Nothing Then Exit Sub n = rngData.Columns.Count For i = n To 2 Step -1 For j = i - 1 To 1 Step -1 If WorksheetFunction.CountA(rngData.Columns(i)) 0 And _ WorksheetFunction.CountA(rngData.Columns(j)) 0 Then arr1 = rngData.Columns(i) arr2 = rngData.Columns(j) If AreEqualArr(arr1, arr2) Then With rngData.Columns(j) 'mark column to be deleted .Copy If MsgBox("Delete marked column?", vbYesNo) _ = vbYes Then rngData.Columns(j).Delete Else 'remove mark Application.CutCopyMode = False End If End With End If End If Next j Next i End Sub
Function AreEqualArr(arr1, arr2) As Boolean Dim i As Long, n As Long AreEqualArr = False For n = LBound(arr1) To UBound(arr1) If arr1(n, 1) arr2(n, 1) Then Exit Function End If Next n AreEqualArr = True End Function