Code to color dupes in row 1 colors only one cell of dupe

Question

I want to check for dupes in Row One

The Code below works fine for column ranges like:

 myrng = Range(\"C2:C\" & Range(\"C65536\").End(x         


        

Answer 1

Use Collections to get the unique values, then loop through the collections to highlight the duplicates.

Sub UsingCollection()
    Dim cUnique As Collection
    Dim Rng As Range
    Dim Cell As Range
    Dim sh As Worksheet
    Dim vNum As Variant
    Dim LstCol As Long
    Dim c As Long, clr As Long, x, r As Range

    Set sh = ThisWorkbook.Sheets("Nodes")
    With sh

        LstCol = .Cells(1, .Columns.Count).End(xlToLeft).Column
        Set Rng = .Range(.Cells(1, 1), .Cells(1, LstCol))
        Set cUnique = New Collection
        Rng.Interior.ColorIndex = xlNone
        clr = 3

        On Error Resume Next
        For Each Cell In Rng.Cells
            cUnique.Add Cell.Value, CStr(Cell.Value)
        Next Cell
        On Error GoTo 0

        For Each vNum In cUnique
            For c = 1 To LstCol
                Set r = .Cells(1, c)
                x = Application.WorksheetFunction.CountIf(.Range(.Cells(1, 1), .Cells(1, c)), r)
                If r = vNum Then
                    If x > 1 Then
                        r.Interior.ColorIndex = clr
                    End If
                End If
            Next c
            clr = clr + 1
        Next vNum

    End With

End Sub