Simple LinQ question: convert [][] to []

Question

Hello,

I would like to get collection or list of Item objects, but I get array of arrays now.

Item[][] s = employees.Select(e => e.Orders.Select(o => new Item(e.ID, o.ID)).ToArray()).ToArray();

Can anyone select me solution to do it?

P.S. just LinQ solution :)

Answer 1

The extension method you're looking for is called "SelectMany": http://msdn.microsoft.com/en-en/library/system.linq.enumerable.selectmany.aspx

Answer 2

You need to use SelectMany to concatenate result sets.

var items = employees.SelectMany(e => e.Orders.Select(o => new Item(e.ID, o.ID)));

Answer 3

Have a look at Enumerables.SelectMany(), see the example in this Stack Overflow question.

Answer 4

For what it's worth, this can be written somewhat more succinctly and clearly in LINQ syntax:

var s = from e in employees
        from o in e.Orders
        select new Item(e.ID, o.ID);