Question

       public DateTime EnterDeparture()
        {
            Console.WriteLine("Enter Year:");
            return new DateTime().AddYears(int.Parse(Console.ReadLine()));
        }
    // This will return new DateTime(Without assigned Year)  Cause DateTime is value type.
           public DateTime EnterDeparture()
                {
                    DateTime EnterDeparture = new DateTime();
                    Console.WriteLine("Enter Year:");
                    EnterDeparture.AddYears(int.Parse(Console.ReadLine()));
                    return EnterDeparture;
                }

How to work with several fields in DateTime ? (Year,Days for example) Default constructors aren’t suitable.

Answer 1

The DateTime.AddXXX methods return new DateTime instances, the existing struct does not change. Since each method returns a new instance, you can chain the method calls together. At the very least, you want to capture each return value into a variable. For example:

DateTime myDate = DateTime.Today;
DateTime tomorrowAtNoon = myDate.AddDays(1).AddHours(12);

You could have also written it like

DateTime tomorrow = myDate.AddDays(1);
DateTime tomorrowAtNoon = tomorrow.AddHours(12);

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