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

namespace Nullable_types
{
    class Program
    {
        static void Main(string[] args)
        {
            //DateTime date = null; //datetime is nott nullable

            Nullable<DateTime> ndate = null;
            DateTime? nullable_date = null;

            /*
            Console.WriteLine("GetValueOrDefault(): " + nullable_date.GetValueOrDefault());
            Console.WriteLine("HasValue: " + nullable_date.HasValue);
            Console.WriteLine("Value: " + nullable_date.Value);
            */
            nullable_date = new DateTime(2014, 1, 1);
            //DateTime date2 = nullable_date;
            DateTime date2 = nullable_date.GetValueOrDefault();
            DateTime? date3 = date2;

            Console.WriteLine(date2);
            Console.WriteLine(date3.GetValueOrDefault());

            DateTime date4;

            //Method 1
            if (nullable_date != null)
                date4 = nullable_date.GetValueOrDefault();
            else
                date4 = DateTime.Today;
            Console.WriteLine(date4);
            //Method 2

            DateTime date5 = nullable_date ?? DateTime.Today;
            Console.WriteLine(date5);

            DateTime date6 = (nullable_date != null) ? nullable_date.GetValueOrDefault() : DateTime.Today;
            Console.WriteLine(date6);

        }
    }
}