Eliminate Duplicates In An Array

[Jacob Roman]

Eliminating duplicates in an array can come in handy for many situations. Like if you have a long list of names, with some of them coming up twice or more times, and you wanted to only list everyone who has a different name, this will do it. But in this example, I used the Long data type instead of String. Here is a simple way to eliminate duplicates in an array:

Option Explicit
 
Dim A(9) As Long
Dim B() As Long
Dim I As Long, J As Long, K As Long
 
Private Sub Remove_Duplicates(Old_Array() As Long, New_Array() As Long)
 
    Dim I As Long, J As Long, K As Long
 
    ReDim New_Array(0) As Long
    Dim Dup As Boolean
    For I = 0 To UBound(Old_Array)
        Dup = False
        For J = 0 To UBound(New_Array)
            If Old_Array(I) = New_Array(J) And I <> 0 Then
              Dup = True
              Exit For
            End If
        Next J
        If Dup = False Then
            ReDim Preserve New_Array(K) As Long
            New_Array(K) = Old_Array(I)
            K = K + 1
        End If
    Next I
 
End Sub
 
Private Sub Form_Activate()
 
    A(0) = 0
    A(1) = 1
    A(2) = 2
    A(3) = 3
    A(4) = 4
    A(5) = 5
    A(6) = 6
    A(7) = 7
    A(8) = 8
    A(9) = 9
 
    Remove_Duplicates A(), B()
    
    For I = 0 To UBound(B)
        Print B(I)
    Next I
 
End Sub