Why do we need iterators in c#?

Question

Can somebody provide a real life example regarding use of iterators. I tried searching google but was not satisfied with the answers.

Answer 1

Simple example : a function that generates a sequence of integers :

static IEnumerable GetSequence(int fromValue, int toValue)
{
    if (toValue >= fromValue)
    {
        for (int i = fromValue; i <= toValue; i++)
        {
            yield return i;
        }
    }
    else
    {
        for (int i = fromValue; i >= toValue; i--)
        {
            yield return i;
        }
    }
}

To do it without an iterator, you would need to create an array then enumerate it...