using System;using System.Collections;public class Person{ public Person(string fName, string lName) {  this.firstName = fName;  this.lastName = lName; } public string firstName; public string lastName;}public class People : IEnumerable{ private Person[] _people; public People(Person[] pArray) {  _people = new Person[pArray.Length];  for (int i = 0; i < pArray.Length; i++)  {   _people[i] = pArray[i];  } } IEnumerator IEnumerable.GetEnumerator() {  return (IEnumerator) GetEnumerator(); } public PeopleEnum GetEnumerator() {  return new PeopleEnum(_people); }}public class PeopleEnum : IEnumerator{ public Person[] _people; // Enumerators are positioned before the first element // until the first MoveNext() call. int position = -1; public PeopleEnum(Person[] list) {  _people = list; } public bool MoveNext() {  position++;  return (position < _people.Length); } public void Reset() {  position = -1; } object IEnumerator.Current {  get  {   return Current;  } } public Person Current {  get  {   try   {    return _people[position];   }   catch (IndexOutOfRangeException)   {    throw new InvalidOperationException();   }  } }}class App{ static void Main() {  Person[] peopleArray = new Person[3]  {   new Person("John", "Smith"),   new Person("Jim", "Johnson"),   new Person("Sue", "Rabon"),  };  People peopleList = new People(peopleArray);  foreach (Person p in peopleList)   Console.WriteLine(p.firstName + " " + p.lastName); }}/* This code produces output similar to the following: * * John Smith * Jim Johnson * Sue Rabon * */