Question

I have a recursive object, a linked list really:

public class LinkedList 
{
    public string UniqueKey { get; set; }
    public LinkedList LinkedList { get; set; }
}

LinkedList will have some object graph that will eventually end in LinkedList.LinkedList == null.

I would like to take all the objects in the graph and put them into a LinkedList collection so that I can iterate over them. How do I do this in C#? I feel as if there’s a really easy way of going about this using yield or Linq voodoo?

Answer 1

Something like this should work. If you have control over the class you can make it IEnumerable directly.

public class LinkedListEnumerable : IEnumerable<string>
{
    LinkedList list;
    public LinkedListEnumerable(LinkedList l)
    {
        this.list = l;
    }

    public IEnumerator<string> GetEnumerator()
    {
        LinkedList l = list;
        while(l != null)
        {
            yield return l.UniqueKey;
            l = l.Next;
        }
    }
}

Then you can iterate over LinkedListEnumerable with a for-each loop.