Subtract a generic list from another

Question

I am trying remove a list of firmIDs from one list from another. I don\'t really understand linq but I am pretty sure I need to use it.

List firm         


        

Answer 1

Contains is the native method of List that expects you to pass in a T. You want Where instead.

var result = firms.Where(i => trackedFirms.Contains(i.FirmID));

If you expect result to be a List then add .ToList() to the end of your Where LINQ expression.