Question

If I have the following structure:

Public Class UserData
    Public ID As String
    Public Name As String
End Class

How can I select it in a conditional like this?

Dim myUsers As New System.Collections.Generic.List(Of UserData)

If myUsers.Contains(.ID = "1") = True Then
    ...

I know that myUsers.Contains(.ID = "1") is totally wrong, but I am curious how to do something like that? Is it possible? Is this a job for LINQ?

Answer 1

How about this:

If myUsers.Any(Function(u) u.ID = "1") Then
   ...

Of course, if you’re going to do this more than once, you’ll probably be better off creating a set to search in:

Dim myUserSet = New HashSet(Of String)(myUsers.[Select](Function(u) u.ID))
For Each userId In selectedUserIds
    If myUserSet.Contains(userId) Then
       ...

My vb is rusty. Please forgive syntax errors