Binaryworld - HasDuplicateValues - Check if an array has duplicate values ... [ VB.net -> Arrays ]

' Returns True if an array contains duplicate values
  ' it works with arrays of any type

  Function HasDuplicateValues(ByVal arr As Array) As Boolean
    Dim ht As New Collections.Hashtable(arr.Length * 2)
    Dim index As Integer

    For index = 0 To arr.Length - 1
      Dim value As Object = arr.GetValue(index)

      If ht.Contains(value) Then
        ' return True if the value is already in the hashtable
        Return True
      Else
        ' else just add it to the hashtable now
        ht.Add(value, Nothing)
      End If
    Next
  End Function