Excel compare two columns and highlight duplicates

Question

I have an excel file with 10,000 rows in column A some values are the same.

Example:

A1 - P7767

A2 - P3443

A3 - P7767

A4 - P8746

A5 - P9435
         


        

Answer 1

I was trying to compare A-B columns and highlight equal text, but usinng the obove fomrulas some text did not match at all. So I used form (VBA macro to compare two columns and color highlight cell differences) codes and I modified few things to adapt it to my application and find any desired column (just by clicking it). In my case, I use large and different numbers of rows on each column. Hope this helps:

Sub ABTextCompare()

Dim Report As Worksheet
Dim i, j, colNum, vMatch As Integer
Dim lastRowA, lastRowB, lastRow, lastColumn As Integer
Dim ColumnUsage As String
Dim colA, colB, colC As String
Dim A, B, C As Variant

Set Report = Excel.ActiveSheet
vMatch = 1

'Select A and B Columns to compare
On Error Resume Next
 Set A = Application.InputBox(Prompt:="Select column to compare", Title:="Column A", Type:=8)
  If A Is Nothing Then Exit Sub
colA = Split(A(1).Address(1, 0), "$")(0)
 Set B = Application.InputBox(Prompt:="Select column being searched", Title:="Column B", Type:=8)
   If A Is Nothing Then Exit Sub
  colB = Split(B(1).Address(1, 0), "$")(0)
 'Select Column to show results
 Set C = Application.InputBox("Select column  to show results", "Results", Type:=8)
    If C Is Nothing Then Exit Sub
  colC = Split(C(1).Address(1, 0), "$")(0)

'Get Last Row
lastRowA = Report.Cells.Find("", Range(colA & 1), xlFormulas, xlByRows, xlPrevious).Row - 1 ' Last row in column A
lastRowB = Report.Cells.Find("", Range(colB & 1), xlFormulas, xlByRows, xlPrevious).Row - 1 ' Last row in column B

 Application.ScreenUpdating = False
'***************************************************
For i = 2 To lastRowA
      For j = 2 To lastRowB
          If Report.Cells(i, A.Column).Value <> "" Then
              If InStr(1, Report.Cells(j, B.Column).Value, Report.Cells(i, A.Column).Value, vbTextCompare) > 0 Then
                  vMatch = vMatch + 1
                  Report.Cells(i, A.Column).Interior.ColorIndex = 35 'Light green background
                  Range(colC & 1).Value = "Items Found"
                  Report.Cells(i, A.Column).Copy Destination:=Range(colC & vMatch)
                  Exit For
              Else
                  'Do Nothing
              End If
          End If
      Next j
  Next i
If vMatch = 1 Then
    MsgBox Prompt:="No Itmes Found", Buttons:=vbInformation
End If
'***************************************************
Application.ScreenUpdating = True

End Sub