The Doena Journal

Deutsche Version

“Yield return” is a powerful and handy statement if you want to quickly and easily an iteratable list without creating an Array or a List first:

using System;
using System.Collections.Generic;
using System.Drawing;

class Program
{
    static void Main()
    {
        var colors = Rainbow;

        Console.WriteLine("colors.GetType(): {0}", colors.GetType());
        Console.WriteLine();

        foreach (Color color in colors)
        {
            Console.WriteLine(color.Name);
        }

        Console.ReadLine();
    }

    static IEnumerable<Color> Rainbow
    {
        get
        {
            yield return (Color.Red);
            yield return (Color.Orange);
            yield return (Color.Yellow);
            yield return (Color.Green);
            yield return (Color.LightBlue);
            yield return (Color.Indigo);
            yield return (Color.Violet);
        }
    }
}

Red
Orange
Yellow
Green
LightBlue
Indigo
Violet

The .NET compiler then creates the necessary IEnumerable- and IEnumerator-implementing classes and the state machine in the background and everything is fine and clear.
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