Select objects in binding list that match criteria using LINQ?

Question

I have a BindingList that contains 100,000 objects. Each object contains a bool property that indicates whether the object has been modified or not. I basically want to loop through the objects and when I find one with that bool property set to true, I want to set it to false. Something similar to this:

foreach (myObject obj in bindingListOfMyObjects)
{
    if (obj.Modified)
    {
        obj.Modified = false;
    }
}

Is it possible to do this using LINQ? And would that be any faster than the code above?

Answer 1

No. There's no way of doing this in LINQ. For this to work, you need to modify the elements directly in the BindingList . LINQ would simply return a new IEnumerable .

Answer 2

You could use Enumerable.Where to filter the collections, and them modify them in your loop:

foreach (myObject obj in bindingListOfMyObjects.Where(o => o.Modified))
     obj.Modified = false;

This will not be any faster, though it may be slightly easier to understand the intent.

Note that you wouldn't, in general, use LINQ to actually make the modifications - LINQ queries, by their nature, should not cause side effect (changing the value). They are intended to be used as queries - so filtering the objects is appropriate, and then setting in a loop. For details, I recommend reading Eric Lippert's post on ForEach vs foreach .