Rob Garrett - Blogs

Another nice addition to C# 2.0 is the yield keyword. Yield enables iterator blocks to provide values to an enumerated result, see the following example.

// yield-example.cs using System; using System.Collections; public class List { public static IEnumerable Power(int number, int exponent) { int counter = 0; int result = 1; while(counter++ < exponent) { result = result * number; yield return result; } } static void Main() { // Display powers of 2 up to the exponent 8: foreach(int i in Power(2, 8)) Console.Write("{0} ", i); } }
What does this mean in English? Essentially, iterator blocks can implicitly create an array of results, which supports IEnumerable, without having to declare an array data type and populating it.

The following line will signal the end of the iteration.
yield break;