C# yield return; yield break;

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using System; using System.Collections;   namespace YieldDemo {           class Program     {         public static IEnumerable Power(int num, int exponent)         {             int counter = 0;             int result = 1;             while (counter++ < exponent)             {                 //if (counter == 4) yield break;                 if (counter == 4) yield return null;                 result = result * num;                 yield return result;             }         }         public static IEnumerator Power2(int num, int exponent)         {             int counter = 0;             int result = 1;             while (counter++ < exponent)             {                 //if (counter == 4) yield break;                 if (counter == 4) yield return null;                 result = result * num;                 yield return result;             }         }         static void Main(string[] args)         {             foreach (var item in Power(2,8))             {                 Console.WriteLine(item);             }               Console.WriteLine("---");             var e = Power2(2, 8);             while (e.MoveNext())             {                 var i = e.Current;                 Console.WriteLine(i);             }               Console.WriteLine("main done");             Console.ReadKey();         }     } }