Constructor body

Question

In this program statement in the constructor method body is expressed in a different way. I wish to know whether this is unique for the DateTime only. Problem is highlighted.

using System;

namespace MethodOverloading
{
public class Time1
{
// private member variables
private int Year;
private int Month;
private int Date;
private int Hour;
private int Minute;
private int Second;

// public accessor methods
public void DisplayCurrentTime()
{
Console.WriteLine("{0}/{1}/{2} {3}:{4}:{5}", Month, Date, Year, Hour, Minute, Second);
}

// constructors
public Time1(DateTime dt)
{
Year = dt.Year;
Month = dt.Month;
Date = dt.Day;
Hour = dt.Hour;
Minute = dt.Minute;
Second = dt.Second;
}

public Time1(int Year, int Month, int Date, int Hour, int Minute, int Second)
{
this.Year = Year;
this.Month = Month;
this.Date = Date;
this.Hour = Hour;
this.Minute = Minute;
this.Second = Second;
}
}

public class MethodOverloadingTester
{
public void Run()
{
DateTime currentTime = DateTime.Now;

Console.WriteLine(currentTime);

Time1 time1 = new Time1(currentTime);

time1.DisplayCurrentTime();

Time1 time2 = new Time1(2000, 11, 18, 11, 03, 30);
time2.DisplayCurrentTime();
}

static void Main()
{
MethodOverloadingTester t = new MethodOverloadingTester();
t.Run();

Console.Read();
}
}
}
/*
9/17/2008 8:25:28
11/18/2000 11:3:30
*/

Vulpes · Answer

Well all that's doing is to give the user an alternative (and more compact) way of creating a Time1 object. Instead of having to pass the fields individually you pass them as a DateTime which conveniently packages them up into a single structure which you then decompose into its constituent parts when setting the fields.

Maha · Answer

Thank you for your explanation.

Vulpes · Answer

Well actually the internal representation of a DateTime is a long integer (8 bytes) which stores the number of 'ticks' since 12:00 midnight January 1 0001. A 'tick' for this purpose is 100 nanoseconds. Code within the DateTime structure converts these ticks to and from a normal date/time representation including years months days hours minutes seconds and milliseconds. This is much more compact than having to store these components individually.

Maha · Answer

If take dt it is 02/12/2014 that means it is a combination of two digits four digits and back slash. How the following code is correctly selecting them. Year = dt.Year; Month = dt.Month; Date = dt.Day; Hour = dt.Hour; Minute = dt.Minute; Second = dt.Second;

Vulpes · Answer

You'd use the compact version if you already had a DateTime that you wanted to create a Time1 object for. Those situations would certain include where you want to use the current date and time since of course this is conveniently available from the DateTime.Now property.

Maha · Answer

So that compact version is applicable if you want to find current date and time.

Michal Habalcik · Answer

What exactly are you trying to achieve? Can you be more specific? The code looks good you have 2 different constructors for the same thing. However try to follow some naming convency private variables starting with upper letter are hurting my eyes ;)

Sibeesh Venu · Answer

There are several usages of this keyword in C#. To qualify members hidden by similar name To have an object pass itself as a parameter to other methods To have an object return itself from a method To declare indexers To declare extension methods To pass parameters between constructors To internally reassign value type (struct) value . To invoke an extension method on the current instance To cast itself to another type To chain constructors defined in the same class You can avoid the first usage by declaring getter and setter for all fields and accessing fields only through properties. In C# 3.0 this can be done easily via automatic properties however you lose the debugging advantage of this approach. http://stackoverflow.com/questions/23250/when-do-you-use-the-this-keyword Please go through that links and understand the usage of this operator.