Excel VBA - Highlighting Duplicate Cell Values - Paragraphs (Long Strings) - excel

Question

I've searched the forums and found some great Excel VBA code to find and highlight duplicate cell values in a given dataset range.
However, the cell values in my dataset are paragraphs. This means some cell values in the dataset will be greater than 255 characters. When I run the code below, duplicate cells are highlighted until the code encounters a cell value greater than 255 charactions. This appears to cause the "countif" function to throw the error:
Run-time error '1004':
Unable to get CountIf property of the WorksheetFunction class
Any ideas on how to pass a Cell.Value greater than 255 characters to CountIf, or another idea to compare cell values greater than 255 characters to highlight duplicates?
Sub findDuplicates()
Const headRow As Integer = 7 'row that contains the table heading row for the dataset
Dim lastRow As Integer
Dim rng As Range
With ThisWorkbook.Worksheets(1)
lastRow = .Range("F" & Rows.Count).End(xlUp).Row 'finds last row in dataset
Set rng = .Range(Cells(headRow + 1, 6), Cells(lastRow, 6)) 'sets the range of the dataset between the headRow and lastRow
End With
For Each Cell In rng
If Application.WorksheetFunction.CountIf(rng, Cell.Value) > 1 Then 'tests if there is a duplicate
Cell.Interior.ColorIndex = 6 'highlight yellow
End If
Next Cell
End Sub

Answer 1

To compare cell values with lengths > 255, you can loop through the range doing a cell by cell comparison.
Please read the comments in the code below for further details, and post back with any questions.
Option Explicit 'require declaration of ALL variables
'go to Tools/Options/Editor and set "Require Variable Declaration"
Option Compare Text 'for case insensitive
Sub findDuplicates()
'Use Long instead of integer
' Plenty of articles as to why
Const headRow As Long = 7 'row that contains the table heading row for the dataset
Dim lastRow As Long
Dim rng As Range
Dim Counter As Long
Dim V As Variant, I As Long, J As Long
Dim COLL As Collection
With ThisWorkbook.Worksheets(1)
lastRow = .Range("F" & Rows.Count).End(xlUp).Row 'finds last row in dataset
Set rng = .Range(Cells(headRow + 1, 6), Cells(lastRow, 6)) 'sets the range of the dataset between the headRow and lastRow
End With
'Read range into vba array for faster processing
V = rng
'loop through the array to do the count
Set COLL = New Collection 'collect the duplicate cell addresses
For I = 1 To UBound(V, 1)
Counter = 0
For J = 2 To UBound(V, 1)
If V(J, 1) = V(I, 1) Then 'duplicate
Counter = Counter + 1
If Counter > 1 Then
On Error Resume Next 'avoid duplicate addresses in the collection
COLL.Add Item:=rng(I).Address, Key:=rng(I).Address
On Error GoTo 0
End If
End If
Next J
Next I
'highlight the relevant cells
rng.Interior.ColorIndex = xlNone
For Each V In COLL
Range(V).Interior.ColorIndex = 6
Next V
End Sub

Answer 2

I propose to convert long text into some numeric value. See my function:
Function UnicodeVal(str As String) As Double
Dim l As Long
Dim dblV As Double
dblV = 1
For l = 1 To Len(str)
If l Mod 2 Then
dblV = dblV * AscW(Mid(str, l, 1))
Else
dblV = dblV / AscW(Mid(str, l, 1))
End If
UnicodeVal = dblV
Next l
The function multiply and divides Unicode values of all character in the string and returns the score. Because it is multiplying for even numbers and dividing for odd, it is immuned from typos like "hoem" instead of "home". It is unlikely that the score will be the same in case of long strings, I think.
You can use this function in place of direct comparisons.