Mình ko biết trong excel có hàm nào hữu dụng ko nma mình có function sau
Function Dem(Rng As Range)
On Error Resume Next
Dim Dic As Object
Dim Cll As Range
Set Dic = CreateObject("Scripting.Dictionary")
With Dic
For Each Cll In Rng
.Add Cll.Value, ""
Next
Dem = .Count
End With
End Function