Question

I have a collection FileTypes that holds objects of type FileType. That type has field CounterpartyId.
I also have a collection Counterparties of objects of type Counterparty, that has field Id.
Could you please help me filter out all Counterparties whose Id is not equal to any FileType’s CounterpartyId, using LINQ.
Thanks

Answer 1

You could use Any() and write something like:

var filteredCounterparties = counterparties.Where(
    cp => !fileTypes.Any(ft => cp.Id == ft.CounterpartyId));