Remove Duplicate Lines from textbox or richtextbox vb.net

Question

Does anyone have any sample code of how to do this? ex:

a
b
b
c
b
d

will end up as

a
b
c
b
d

You could also use a Dictionary. Example:http://www.dotnetperls.com/dictionary — NoChance, Jun 28 '15 at 13:38
possible duplicate of [Efficient list of unique strings C#](http://stackoverflow.com/questions/918742/efficient-list-of-unique-strings-c-sharp) — Bjørn-Roger Kringsjå, Jun 28 '15 at 13:39

score 2 · Accepted Answer · answered Jun 28 '15 at 16:02

It looks to me like you want to remove repeating lines, and not simply get a list of distinct values (as demonstrated by the presence of the 'b' before the 'd' in the desired output).

If so, you can use code like this:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim lines As New List(Of String)(TextBox1.Lines)
    For i As Integer = lines.Count - 1 To 1 Step -1
        If lines(i) = lines(i - 1) Then
            lines.RemoveAt(i)
        End If
    Next
    TextBox1.Lines = lines.ToArray
End Sub

Remove Duplicate Lines from textbox or richtextbox vb.net

1 Answers1