[RESOLVED] Eliminate Duplicates In Array

[Jacob Roman]

I'm trying to eliminate duplicates from one array, and store them into another, but this code doesn't seem to do it right. Can anyone give me a hand on fixing it. Thanks in advance.

[EDIT] Fixed subscript out of range error.

Option Explicit
 
Dim A(9) As Long
Dim B() As Long
Dim I As Long, J As Long, K As Long
 
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
    
    ReDim B(0) As Long
 
    For I = 0 To UBound(A)
        For J = 0 To UBound(B)
            If A(I) <> B(J) Then
                If J = UBound(B) Then
                    B(J) = A(I)
                    K = K + 1
                    ReDim Preserve B(K) As Long
                End If
            ElseIf A(I) = B(J) Then
                Exit For
            End If
        Next J
    Next I
    
    For I = 0 To UBound(B)
        Print B(I)
    Next I
 
End Sub

[Jumpercables]

I dont believe that your code it getting inside the 2nd for loop, because your going from 0 to Ubound(B) ( Ubound(B) = 0 ).

[Jacob Roman]

Ok I got it, but the only way it can work right is if the array B(0) has a value that is not 0. So I made it -1 but that's not good. Any other solutions? Here's the more improved code:

Option Explicit
 
Dim A(9) As Long
Dim B() As Long
Dim I As Long, J As Long, K As Long
 
Private Sub Form_Activate()
 
    A(0) = 0
    A(1) = 0
    A(2) = 2
    A(3) = 3
    A(4) = 4
    A(5) = 5
    A(6) = 6
    A(7) = 7
    A(8) = 8
    A(9) = 9
    
    ReDim B(0) As Long
 
    [b]B(0) = -2147483648#[/b]
 
    For I = 0 To UBound(A)
        For J = 0 To UBound(B)
            If A(I) <> B(J) Then
                If J = UBound(B) Then
                    [b]ReDim Preserve B(K) As Long
                    B(K) = A(I)          'I replaced J with K
                    K = K + 1[/b]
                End If
            ElseIf A(I) = B(J) Then
                Exit For
            End If
        Next J
    Next I
    
    For I = 0 To UBound(B)
        Print B(I)
    Next I
 
End Sub

[dglienna]

This seems to do the trick:

Option Explicit
 
Dim A(9) As Long
Dim B() As Long
Dim I As Long, J As Long, K As Long
 
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
    
    ReDim B(0) As Long
    Dim dup As Boolean
    For I = 0 To UBound(A)
        dup = False
        For J = 0 To UBound(B)
            If A(I) = B(J) And I <> 0 Then
              dup = True
              Exit For
            End If
        Next J
        If dup = False Then
            B(J - 1) = A(I)
            K = K + 1
            ReDim Preserve B(K) As Long
        End If
    Next I
    
    For I = 0 To UBound(B) - 1
        Print B(I)
    Next I
End Sub

K seemed to have one extra, which was 0, so I don't show it, and I checked that i<>0 (for the first time thru)

[Jacob Roman]

I dont believe that your code it getting inside the 2nd for loop, because your going from 0 to Ubound(B) ( Ubound(B) = 0 ).

It has to. And updates the second array, making it have more elements for how ever many from the first array is not a duplicate.


Oh and dglienna, I found a better way, but I don't like the idea of making the first element of B() a non zero value.

[Jacob Roman]

Oh nevermind, I'll just make B(0) = -2147483648#, since odds are, it'll never be that number. I updated the above code.

[dglienna]

Did you try mine? It works fine with all conditions. I would sort the info first, though. Use a bubble sort. I thought my version was good, though. That's why I posted it for you.

[Jacob Roman]

Yours had an extra element in the array. Mine didn't. But it was nice to see a variation of it.

[dglienna]

If you know it's going to be there, it's easy enough to redim out. I was following your logic of adding the elements. Plus, I think mine would be faster.

[Jacob Roman]

Hehe, I fixed your version of it, with the help of my solution:

Option Explicit
 
Dim A(9) As Long
Dim B() As Long
Dim I As Long, J As Long, K As Long
 
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
    
    ReDim B(0) As Long
    Dim dup As Boolean
    For I = 0 To UBound(A)
        dup = False
        For J = 0 To UBound(B)
            If A(I) = B(J) And I <> 0 Then
              dup = True
              Exit For
            End If
        Next J
        If dup = False Then
           [b]ReDim Preserve B(K) As Long
            B(K) = A(I)    'I replaced J with K
            K = K + 1[/b]
        End If
    Next I
    
    For I = 0 To UBound(B)
        Print B(I)
    Next I
End Sub

[Jacob Roman]

I even created a Sub out of it to make it easier

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