Does Class need to implement IEnumerable to use Foreach

Question

This is in C#, I have a class that I am using from some else\'s DLL. It does not implement IEnumerable but has 2 methods that pass back a IEnumerator. Is there a way I can u

Answer 1

For a class to be usable with foeach all it needs to do is have a public method that returns and IEnumerator named GetEnumerator(), that's it:

Take the following class, it doesn't implement IEnumerable or IEnumerator :

public class Foo
{
    private int[] _someInts = { 1, 2, 3, 4, 5, 6 };
    public IEnumerator GetEnumerator()
    {
        foreach (var item in _someInts)
        {
            yield return item;
        }
    }
}

alternatively the GetEnumerator() method could be written:

    public IEnumerator GetEnumerator()
    {
        return _someInts.GetEnumerator();
    }

When used in a foreach ( Note that the no wrapper is used, just a class instance ):

    foreach (int item in new Foo())
    {
        Console.Write("{0,2}",item);
    }

prints:

1 2 3 4 5 6