using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var languages = new List<Language> {

            new Language { Name = "C#", SingleLineCommentMarker = "//" },

            new Language { Name = "Perl", SingleLineCommentMarker = "#" },

        };

        foreach (var lang in from Language l in languages where l.SingleLineCommentMarker == "//" select l.Name) { Console.Write("{0}, ", lang); }

    }

    private class Language {

        public string Name { get; set; }

        public string SingleLineCommentMarker { get; set;}

    }

}