Say you have two lists. You want to remove the items from the first list that already exist in a second list:
Dim listFirst As List(Of String) = New List(Of String)
Dim listSecond As List(Of String) = New List(Of String)
listFirst.Add("A")
listFirst.Add("B")
listFirst.Add("C")
listFirst.Add("D")
listFirst.Add("E")
listFirst.Add("F")
listSecond.Add("A")
listSecond.Add("D")
listSecond.Add("F")
Dim different As IEnumerable(Of String) = listFirst.Except(listSecond)
listFirst = different.ToList()
Result:
B
C
E
