Question

Let’s say I have a list of objects:

var items = new {
    new { Order = 0 },
    new { Order = 1 },
    new { Order = -1 },
    new { Order = 3 },
    new { Order = 2 },
    new { Order = -1 }
};

I need to order it so that items with Order > -1 be on top of the list ordered by Order ascending, and remaining items with Order == -1 were following them.

Is there a more elegant way of doing this than using Conact() and Where() clauses:

var orderedItems = items.Where(x => x.Order > -1).OrderBy(x => x.Order)
                   .Conact(items.Where(x => x.Order == -1);

So that after sorting this list would look like:

var items = new {
    new { Order = 0 },
    new { Order = 1 },
    new { Order = 2 },
    new { Order = 3 },
    new { Order = -1 },
    new { Order = -1 }
};

Also items list in actual scenario is already a complex IQueryable<T> object. That’s why I am trying to find the most optimal way of doing such selective ordering.

Answer 1

You could try this – it produces the result you expect:

items.OrderBy(x.Order => x.Order == -1).ThenBy(x.Order => x.Order);