How to: Create an Iterator Block for a List of Integers
Important This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here. ArchiveDisclaimer

How to: Create an Iterator Block for a List of Integers (C# Programming Guide)

In this example, an array of integers is used to build the list SampleCollection. A for loop iterates through the collection and yield returns the value of each item. Then a foreach loop is used to display the items of the collection.

// Declare the collection: 
public class SampleCollection
{
    public int[] items;

    public SampleCollection()
    {
        items = new int[5] { 5, 4, 7, 9, 3 };
    }

    public System.Collections.IEnumerable BuildCollection()
    {
        for (int i = 0; i < items.Length; i++)
        {
            yield return items[i];
        }
    }
}

class MainClass
{
    static void Main()
    {
        SampleCollection col = new SampleCollection();

        // Display the collection items:
        System.Console.WriteLine("Values in the collection are:");
        foreach (int i in col.BuildCollection())
        {
            System.Console.Write(i + " ");
        }

        // Keep the console window open in debug mode.
        System.Console.WriteLine("Press any key to exit.");
        System.Console.ReadKey();
    }
}
/* Output:
    Values in the collection are:
    5 4 7 9 3        
*/
Show:
© 2016 Microsoft