Having trouble using Linq to return unique values when comparing two lists

[AntonyL]

Hello,

I have two lists,
List 1, TeamsList contains 18 unique values (the complete list)
List 2, sortplayinglist can contain anywhere from 2 to 18 unique values (a subset of the complete list)

The values, while unique for each list, are the same. I am simply wanting to get a list of what isn't in list 2 when compared to list one which is the complete list

I am trying to create a third list called notplayingteamslist that only contains the values from the TeamsList that do not appear in the sortplayinglist

Dim notplayingteamslist = TeamsList.except(sortplayinglist)
If notplayingteamslist.count > Nothing Then
    For Each team As String In notplayingteamslist
          Debug.Print(team)
    Next
End If

After working through the microsoft references for Linq, I boiled it down to the code above,
but unfortunately nothing gets populated into notplayingteamslist.

Any hints are greatly appreciated.

Regards,
Antony

[.paul.]

Dim notplayingteamslist As ??? = TeamsList.except(sortplayinglist)

If notplayingteamslist.count > Nothing Then ‘ ???

If notplayingteamslist.count > 0 Then

If The 3 Lists are of type List(Of String), be aware that inconsistent naming or character casing won’t work.
This is how LINQ Except works…

Dim allList As New List(Of String)(New String() {“One”, “Two”, “Three”, “Four”, “Five”})
Dim oddList As New List(Of String)(New String() {“One”, “Three”, “Five”}) 
Dim evenList As List(Of String) =allList.Except(oddList).ToList

[AntonyL]

Thanks Paul,

Your tips put me on the right track

Here is the code that works

Dim teamslist As IEnumerable(Of String) = Global.TeamsList
Dim notplayingteamslist As IEnumerable(Of String) = teamslist.Except(playinglist)
If notplayingteamslist.Count > Nothing Then
    For Each team As String In notplayingteamslist
        Debug.Print(team)
    Next
End If

I had to clone the global variable I was using and make it a local string array.
Not really understanding why the global variable wouldn't work with except.
The conditional is only to catch a null value so that I don't get an out of range error.

Cheers.