Count number of different values in chosen (large) range in VBA?

Question

How can I count the number of different values (numbers and strings mixed) in a chosen (large) range in VBA?

I think about this in this way:
1. Read in data into one dimensional array.
2. Sort array (quick or merge sort) need to test which
3. Simply count number of different values if sorted array : if(a[i]<>a[i+1]) then counter=counter+1.

Is it the most efficient way to solve this problem?

Edit: I want to do it in Excel.

Answer 1

Here is a VBA Solution

You don't need an Array to get this done. You can also use a collection. Example

Sub Samples()
    Dim scol As New Collection

    With Sheets("Sheet1")
        For i = 1 To 100 '<~~ Assuming the range is from A1 to A100
            On Error Resume Next
            scol.Add .Range("A" & i).Value, Chr(34) & _
            .Range("A" & i).Value & Chr(34)
            On Error GoTo 0
        Next i
    End With

    Debug.Print scol.Count

    'For Each itm In scol
    '   Debug.Print itm
    'Next
End Sub

FOLLOWUP

Sub Samples()
    Dim scol As New Collection
    Dim MyAr As Variant

    With Sheets("Sheet1")
        '~~> Select your range in a column here
        MyAr = .Range("A1:A10").Value

        For i = 1 To UBound(MyAr)
            On Error Resume Next
            scol.Add MyAr(i, 1), Chr(34) & _
            MyAr(i, 1) & Chr(34)
            On Error GoTo 0
        Next i
    End With

    Debug.Print scol.Count

    'For Each itm In scol
    '   Debug.Print itm
    'Next
End Sub