Enumerables in

About Enumerables

Types that implement the IEnumerable<T> interface are known as being enumerable. All built-in collection types implement this interface.

An enumerable type can be iterated over using a foreach loop:

var primes = new[] { 2, 3, 5, 7 };
foreach (var prime in primes)
{
    Console.Write(prime);
}
// => 2357

To implement IEnumerable<T>, a type has to implement one method: IEnumerator<T> GetEnumerator(). As seen, an enumerable defers the actual iterating over a collection to an IEnumerator<T> type. This interface has one property and three methods to implement:

• public T Current { get; }: get the current element.
• public bool MoveNext ();: move to the next element, returning true if the move to the next element was successful, and false if not (no more elements).
• public void Reset ();: reset the enumerator to its initial state (before the first element).