Examples: enum, namespace

using System;

using nsClass1 = MyNamespace.Class1;
// using lsClass1 = Lesson7_1.Class1;  // Ошибка, т.к. Class1 не входит в пространство имён Lesson7_1

namespace Lesson7_1
{
    class Program
    {
        enum EnumName
        {
            Pavel = 3,
            Oleg = 2,
            Anna = 10,
            Andrew,
            Gena = 5,
            Elena
        };

        enum daysOfWeek
        {
            sun=7,
            mon=1,
            tue,
            wed,
            thu,
            fri,
            sat,
        }

        static String[] days = {
            "",
            "mon",
            "tue",
            "wed",
            "thu",
            "fri",
            "sat",
            "sun",
        }; 

        static void Main(string[] args)
        {
            Console.WriteLine("Enum EnumName: ");
            EnumName names;
            Array mas = Enum.GetValues(typeof(EnumName));
            foreach (EnumName name in mas)
                Console.WriteLine(name);

            names = EnumName.Oleg;
            Console.WriteLine($"\nEnumName.Oleg value: {EnumName.Oleg}");
            Console.WriteLine($"\nEnumName.Oleg index: {(int)EnumName.Oleg}");


            Console.WriteLine($"\nIndex of \'sat\': {(int)daysOfWeek.sat}");
            Console.WriteLine($"Value of array with index of \'sat\': {days[(int)daysOfWeek.sat]}");
            Console.WriteLine($"\nIndex of \'sun\': {(int)daysOfWeek.sun}");
            Console.WriteLine($"Value of array with index of \'sun\': {days[(int)daysOfWeek.sun]}");
            
            nsClass1 cl1 = new nsClass1();
        }
    }
}

namespace MyNamespace
{
    class Class1 { }
}