using System;

public class Program

{

    public static void Main()

    {

        Nullable<DateTime> date1 = null;        

        DateTime? date2 = null;

        Console.WriteLine("GetValueOrDefault: " + date1.GetValueOrDefault());

        Console.WriteLine("HasValue: " + date1.HasValue);

        //Console.WriteLine("GetValue: " + date1.Value);

        // Nullable DateTime into DateTime

        DateTime? date3 = new DateTime(2018, 1, 1);

        DateTime date4 = date3.GetValueOrDefault();

        // No casting required

        DateTime date5 = date4;

        Console.WriteLine(date4);

        Console.WriteLine(date5);

        // Null Coalescing Operator

        DateTime? date6 = null;

        DateTime date7 = date6 ?? DateTime.Today;       

        // Ternary conditional operator

        DateTime date8 = (date6 != null) ? date6.GetValueOrDefault() : DateTime.Today;

        Console.WriteLine(date7);

        Console.WriteLine(date7);       

    }

}