Value type + reference type

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ValueTypeVsReferenceType
{
    internal class Program
    {
        static void Main(string[] args)
        {
            ReferenceType akarmi = new ReferenceType();

            int number = 10;
            PrintNumber(akarmi.asd);

            ArrayExample array = new ArrayExample();
            array.Initialize();


            BoxingExample boxingExample = new BoxingExample();

            object boxedNumber = boxingExample.BoxNumber(42);

        }

        private static void PrintNumber(ReferenceType referenceType)
        {
            Console.WriteLine(referenceType);
            referenceType.asd = 30;
        }

        public static void PrintNumber(int asd)
        {
            Console.WriteLine(asd);
            asd = 30;
        }
    }

    public class ReferenceType
    {
        public static int Vaaaaa;

        public static int Vaaaaa2 = GetLofac();
        private static int GetLofac() => 5 + Vaaaaa;

        public int asd = GetLofac();

        static ReferenceType()
        {
            Vaaaaa = 22;
        }

        public int MyProperty => 10;

        public int MyProperty2
        {
            get
            {
                return 10;
            }
        }

        public ReferenceType()
        {
            MyProperty6 = "555";
        }

        public string MyProperty3 => "valami";

        public readonly string MyProperty5 = "valami";

        public string MyProperty6 { get; } = Calculate();


        private static string Calculate()
        {
            return "valami" + "_20";
        }

        public string MyProperty4
        {
            get
            {
                return "valami";
            }
        }
    }

    public class ArrayExample
    {
        public void Initialize()
        {
            int[] array = new int[10];
            string valami = "empty";
            ChangeString(valami);
            Console.WriteLine(valami);
        }

        public void ChangeString(string str)
        {
            str = "hehehehee";

            MyEnum two = MyEnum.None;
            MyEnum three = MyEnum.Three;

            int first = (int)two;
            int second = (int)three;

            MyEnum flag = MyEnum.One | MyEnum.Two;

            int flagInt = 1 | 2;

            if ((flag & MyEnum.One) == MyEnum.One)
            {
                if ((flag & MyEnum.Two) == MyEnum.Two)
                {
                    string valami2 = null;
                    string valami3 = valami2 ?? "lel";
                    string valami4 = valami2 == null ? "lel" : valami2;

                    Nullable<bool> valami = new Nullable<bool>();

                    if (valami.HasValue)
                    {
                        Console.WriteLine(valami.Value);
                    }
                }
            }
        }
    }


    public class BoxingExample
    {
        public object BoxNumber(int number)
        {
            return number;
        }
    }

    public enum MyEnum
    {
        None = 8,
        One = 1,
        Two = 2,
        Three = 8,
    }

    class Example
    {
        static int x = 1;
        int y = 2;
        static Example() { Console.WriteLine("Static constructor"); }
        public Example() { Console.WriteLine("Instance constructor"); }
    }



}