Question

I like Lambdas a lot, but I do have trouble with this expression:

Dim Test as New List/of String)
Test.add("A")
Test.add("B")

Dim Adress=Test.Indexof(Function (adr) (Trim(Ucase(Adr)) LIke "A")

The compiler warns that Stirng is no delegate and will not compile – any Ideas how to solve this?

Answer 1

List.IndexOf takes a T and returns the index of that object. So you cannot pass a predicate here. I assume you want the first index of a address that equals-ignore-case “A”. Then you can use Linq:

Dim matches = Test.Select(Function(Address, Index) New With {Address, Index}).
                   Where(Function(x) x.Address.ToUpper = "A")
If matches.Any() Then
    Dim firstMatch = matches.First()
    Dim firstMatchIndex As Int32 = firstMatch.Index '  0 
    Dim firstMatchAddress As String = firstMatch.Address ' "A"
End If