Excel VBA - Collection error - excel

Question

I am trying to build a collection and take the Count of Unique Values from that Collection but am getting an error in building a Collection itself. Can anyone suggest me where I am going wrong. Kindly Share your thoughts. Please let me know how to find out the COUNT of UNIQUE VALUES as well.
Sub trial()
Dim sampleVisualBasicColl As Collection
For i = 2 To 10
Rng = Range("M" & i).value
StartsWith = Left(Rng, 3)
If StartsWith = "Joh" Then
sampleVisualBasicColl.Add Rng
Else
End If
Next
Debug.Print (sampleVisualBasicCol1)
End Sub

Answer 1

Using a collection you can just add Joh to the collection and then count the items:
'Using a collection
Sub Col_test()
Dim cCol As Collection
Dim i As Long
Set cCol = New Collection
On Error GoTo Err_Handler
With ThisWorkbook.Worksheets("Sheet1")
For i = 2 To 20
If Left(.Cells(i, 13), 3) = "Joh" Then
cCol.Add .Cells(i, 13).Value, .Cells(i, 13).Value
End If
Next i
End With
Debug.Print cCol.Count
On Error GoTo 0
Exit Sub
Err_Handler:
Select Case Err.Number
Case 457 'This key is already associated with an element of this collection
Err.Clear
Resume Next
Case Else
MsgBox "Error " & Err.Number & vbCr & _
" (" & Err.Description & ") in procedure Col_test."
Err.Clear
End Select
End Sub
If you want the count of each item (Joh, Ben... whatever else you have) then use a dictionary:
'Using a dictionary.
Sub Dic_Test()
Dim dict As Object
Dim i As Long
Dim sValue As String
Dim key As Variant
Set dict = CreateObject("Scripting.Dictionary")
With ThisWorkbook.Worksheets("Sheet1")
For i = 2 To 20
If Len(.Cells(i, 13)) >= 3 Then
sValue = Left(.Cells(i, 13), 3)
If dict.exists(sValue) Then
dict(sValue) = dict(sValue) + 1
Else
dict(sValue) = 1
End If
End If
Next i
End With
For Each key In dict.keys
Debug.Print key & " = " & dict(key)
Next key
End Sub
Note: I'm using Cells within the code rather than Range. Cells(2,13) is M2 (13th column, 2nd row).
I find this link very helpful with dictionaries: https://excelmacromastery.com/vba-dictionary/
As a further update (after answer accepted) and using the lists you gave in your question here: Excel VBA - Formula Counting Unique Value error this code with dictionaries will return Joh = 4, Ian = 3
'Using a dictionary.
Sub Dic_Test()
Dim dict As Object
Dim dictFinal As Object
Dim i As Long
Dim sValue As String
Dim key As Variant
Dim keyFinal As String
Set dict = CreateObject("Scripting.Dictionary")
Set dictFinal = CreateObject("Scripting.Dictionary")
'Get the unique values from the worksheet.
With ThisWorkbook.Worksheets("Sheet1")
For i = 2 To 20
If Len(.Cells(i, 13)) >= 3 Then
sValue = .Cells(i, 13).Value
If dict.exists(sValue) Then
dict(sValue) = dict(sValue) + 1
Else
dict(sValue) = 1
End If
End If
Next i
End With
'Count the unique values in dict.
For Each key In dict.keys
keyFinal = Left(key, 3)
If dictFinal.exists(keyFinal) Then
dictFinal(keyFinal) = dictFinal(keyFinal) + 1
Else
dictFinal(keyFinal) = 1
End If
Next key
For Each key In dictFinal.keys
Debug.Print key & " = " & dictFinal(key)
Next key
End Sub

Answer 2

You need to create the collection as well as declaring it.
Sub trial()
Dim myCol As Collection
Set myCol= New Collection ' creates the collection
For i = 2 To 10
Rng = Range("M" & i).value
StartsWith = Left(Rng, 3)
If StartsWith = "Joh" Then
myCol.Add Rng
Else
End If
Next
For each x in myCol
Debug.Print x
Next x
End Sub

Answer 3

Hey this code will help u since it's collecting Unique values in Listbox,,
Private Sub UserForm_Initialize()
Dim cUnique As Collection
Dim Rng As Range
Dim Cell As Range
Dim sh As Worksheet
Dim vNum As Variant
Set sh = ThisWorkbook.Sheets("Sheet1")
Set Rng = sh.Range("A2", sh.Range("A2").Value ="John". End(xlDown))
Set cUnique = New Collection
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
Me.ListBox1.AddItem vNum
Next vNum
End Sub

Answer 4

You have not declared Variable Rng & i these are the most important thing to do. Meanwhile I would like to suggest this Formula,,
=Sum(if(Frequency (if(Len(B2 :B20) >0,Match(B2 :B20, B2 :B20, 0),""),if(Len(B2 :B20) >Match(B2 :B20, B2 :B20, 0),"",))>0,1))
Its Array formula so finish with Ctrl +shift +enter.
You can use this one also,
Sub CountUnique()Dim i, count, j As Integer count = 1 For i = 1 To 470 flag = False If count
1 Then For j = 1 To count If Sheet1.Cells(i,
3).Value = Sheet1.Cells(j, 11).Value Then flag
= True End If Next j Else flag = False End If If flag = False Then Sheet1.Cells(count,
11 ).Value = Sheet1.Cells(i, 3).Value count = count + 1 End IfNext i Sheet1.Cells( 1 ,
15 ).Value = count End Sub