suggestions for a macro to find duplicates in a SINGLE column

Question

found a lot of questions involving finding duplicates in two columns :

i.e. MS Excel how to create a macro to find duplicates and highlight them? and excel mark duplicates values

However I'm trying to adapt code to be used to find duplicates in one column. For example here is a data set:

Column 1

Foo
Bar
23
23
12
foo
Bar
bart

This is what I'm using right now:

Function warnDupes()

Dim lastRow As Long
Dim dict As Object

' Let Col be the column which warnDupes operates on.
Dim Col As String

Col = "A"

Set dict = CreateObject("scripting.dictionary")

lastRow = range(Col & Rows.Count).End(xlUp).Row

On Error Resume Next
For i = lastRow To 1 Step -1
    If dict.Exists(range(Col & i).value) = True Then

    'range("Y" & i).EntireRow.Delete

    MsgBox ("Hmm...Seems to be a duplicate of " & range(Col & i).value & _
    " in Cell " & Col & i)

End If
dict.Add range(Col & i).value, 1
Next

End Function

So far I've got some code that does 90% of the job. 23 and 23 are matched. Bar and Bar are matched. etc. So the code matches both Strings and Ints. But I'd like the macro to be able to match Foo and foo as a duplicate as well. How do I make Excel ignore case?

This question ( Function for detecting duplicates in Excel sheet ) seems relevent but I'm having trouble adapting the code or understanding what the author did. Any improvements to the code, explanations or suggestions would be very much appreciated.

Thanks.

UPDATE:

Just noticed something really weird.

The data:

IB6061
IC6071

are matched whether I use my Macro or if I use the Conditional Formatting tool in Excel. Any reason why?

Solution 1

On your Exists() & .Add() lines, make both values the same case:

If dict.Exists(UCase$(Range(Col & i).Value)) Then

and

dict.Add UCase$(Range(Col & i).Value), 1

That way the duplicates will always be added to the dictionary in uppercase and so case will never matter.

Solution 2

franklin

Why not an Excel formula?

If the values are in Col A then type this in Cell B1 and copy it down?

=IF(COUNTIF(A:A,A1)>1,"It is a duplicate","It is not a duplicate")

It will also work for cases like "Foo" and "foo"

You can then also use Conditional Formatting using the above formula to highlight duplicates?

FOLLOWUP

The data:

IB6061

IC6071

are matched whether I use my Macro or if I use the Conditional Formatting tool in Excel.

Any reason why?

What formula are you using?

This works for me. Highlight Col A and then use this formula

=COUNTIF(A:A,A1)>1

See snapshot

Sid

Solution 3

You could put all the keys in lower case, for example:

Dim myKey as String

For i = lastRow To 1 Step -1
    myKey = UCase(range(Col & i).value)
    If dict.Exists(myKey) = True Then

    'range("Y" & i).EntireRow.Delete

    MsgBox ("Hmm...Seems to be a duplicate of " & range(Col & i).value & _
    " in Cell " & Col & i)

    Else
        dict.Add myKey, 1
    End If
Next i

Solution 4

This Works for me

Excel 2007

Sub removeDuplicate(rg As Range, col as Integer)
    rg.RemoveDuplicates Columns:=col, Header:=xlYes
End Sub

Excel 2003

' Excel 2003
Option Explicit

Sub DeleteDups(range as String) 

    Dim x               As Long 
    Dim LastRow         As Long 

    ' Range "A65536" 
    LastRow = Range(range).End(xlUp).Row 
    For x = LastRow To 1 Step -1 
        If Application.WorksheetFunction.CountIf(Range("A1:A" & x), Range("A" & x).Text) > 1 Then 
            Range("A" & x).EntireRow.Delete 
        End If 
    Next x 

End Sub

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Comments

[Alex K.]

Don't forget to add as upper case also

[Reafidy]

The remove duplicates function is available in Excel 2007 onwards.

[Reafidy]

+1 for the follow up using conditional formatting which is perfect for finding and highlighting duplicates.