Csharp_Chap13

1) The document discusses collection classes in C# and how to implement a class to be used in a foreach loop. 2) A class needs to implement the IEnumerator interface and include methods like GetEnumerator(), MoveNext(), Reset(), and Current. 3) An example class xxx is implemented that iterates through an array, tracking the index with a variable i. It returns strings from the array on each MoveNext() call until i equals the array length.