C# Lists: How to copy elements from one list to another, but only certain properties

Question

So I have a list of objects with a number of properties. Among these properties are name and id. Let's call this object ExtendedObject. I've also declared a new List of different objects that have only the properties name and id. Let's call this object BasicObject.

What I'd like to do is convert or copy (for lack of better words) the List of ExtendedObject objects to a list of BasicObject objects. I know C# Lists have a lot of interesting methods that can be useful, so I wondered if there were an easy way to say something to the effect of:

basicObjectList = extendedObjectList.SomeListMethod<BasicObject>(some condition here);

But I realize it may end up looking nothing like that. I also realize that I could just loop through the list of ExtendedObjects, create a new BasicObject from each ExtendedObject's name and id, and push it onto a list of BasicObjects. But I was hoping for something a little more elegant than that.

Does anyone have any ideas? Thanks very much.

Answer 1

It depends on exactly how you'd construct your BasicObject from an ExtendedObject, but you could probably use the ConvertAll method:

List<BasicObject> basicObjectList =
    extendedObjectList.ConvertAll(x => new BasicObject
                                           {
                                               id = x.id,
                                               name = x.name
                                           });

Or, if you prefer, you could use the LINQ Select method and then convert back to a list:

List<BasicObject> basicObjectList =
    extendedObjectList.Select(x => new BasicObject
                                       {
                                           id = x.id,
                                           name = x.name
                                       }).ToList();