Are Multiple Iterators possible in c=C#?

Question

Are multiple iterators (for a single class or object) possible in C# .NET? If they are, give me some simple examples.

Sorry if the question is not understandable and please make me clear.

Answer 1

You could certainly create different iterators to traverse in different ways. For example, you could have:

public class Tree<T>
{
    public IEnumerable<T> IterateDepthFirst()
    {
        // Iterate, using yield return
        ...
    }

    public IEnumerable<T> IterateBreadthFirst()
    {
        // Iterate, using yield return
        ...
    }
}

Is that the kind of thing you were asking?

You could also potentially write:

public class Foo : IEnumerable<int>, IEnumerable<string>

but that would cause a lot of confusion, and the foreach loop would pick whichever one had the non-explicitly-implemented GetEnumerator call.

You can also iterate multiple times over the same collection at the same time:

foreach (Person person1 in party)
{
    foreach (Person person2 in party)
    {
        if (person1 != person2)
        {
            person1.SayHello(person2);
        }
    }
}