Click here to Skip to main content
Click here to Skip to main content

Writing Hello World in different styles using C# and .NET

By , 11 Jan 2004
Rate this:
Please Sign up or sign in to vote.

Introduction

I’ve attempted to write the traditional ‘Hello World’ in different styles. This explores the different possibilities of addressing a problem – ‘Hello World’ with different features of the C# language and the .NET framework.

The implementations

1. A Beginners Hello World

public class HelloWorld
{ 
  public static void Main()
  {
    System.Console.WriteLine("HELLO WORLD");
  }
}

2. Slightly improved version

using System;

public class HelloWorld
{ 
  public static void Main()
  {
    Console.WriteLine("HELLO WORLD");
  }
} 

3. Command Line Arguments

using System;

public class HelloWorld
{ 
  public static void Main(string[] args)
  {
    Console.WriteLine(args[0]);
  }
} 

4. From Constructor

using System;
public class HelloWorld
{ 
  public HelloWorld()
  {
    Console.WriteLine("HELLO WORLD");
  }

  public static void Main() 
  {
    HelloWorld hw = new HelloWorld(); 
  }
}

5. More OO

using System;
public class HelloWorld
{ 
  public void helloWorld()
  {
    Console.WriteLine("HELLO WORLD");
  }

  public static void Main() 
  {
    HelloWorld hw = new HelloWorld();
    hw.HelloWorld(); 
  }
}

6. From another class

using System;
public class HelloWorld
{ 
  public static void Main()
  {
    HelloWorldHelperClass hwh = new HelloWorldHelperClass();
    hwh.writeHelloWorld(); 
  }
} 

public class HelloWorldHelperClass
{ 
  public void writeHelloWorld() 
  {
    Console.WriteLine("Hello World"); 
  }
} 

7. Inheritance

abstract class HelloWorldBase
{
  public abstract void writeHelloWorld();
}
class HelloWorld : HelloWorldBase
{
  public override void writeHelloWorld() 
  { 
    Console.WriteLine("Hello World");
  }
}
class HelloWorldImp
{
  static void Main() {
    HelloWorldBase hwb = HelloWorld;
    HelloWorldBase.writeHelloWorld();
  }
}

8. Static Constructor

using System;
public class HelloWorld
{ 
  private static string strHelloWorld;

  static HelloWorld()
  {
    strHelloWorld = "Hello World";
  }
  void writeHelloWorld()
  {
    Console.WriteLine(strHelloWorld);
  }

  public static void Main() 
  {
    HelloWorld hw = new HelloWorld();
    hw.writeHelloWorld(); 
  }
}

9. Exception Handling

using System;

public class HelloWorld
{ 
  public static void Main(string[] args)
  {
    try
    {
      Console.WriteLine(args[0]);
    }
    catch(IndexOutOfRangeException e)
    {
      Console.WriteLine(e.ToString());
    }
  }
}

10. Creating a DLL and using it in an application

using System;

namespace HelloLibrary
{
  public class HelloMessage
  {
    public string Message
    {
      get
      {
        return "Hello, World!!!";
      }
    }
  } 
}

//------

using System;
using HelloLibrary;

namespace HelloApplication
{
  class HelloApp
  {

    public static void Main(string[] args)
    {
      HelloMessage m = new HelloMessage();

    }
  }
}

11. Using Property

using System;
public class HelloWorld
{ 
  public string strHelloWorld
  {
    get
    {
      return "Hello World";
    }
  }

  public static void Main() 
  {
    HelloWorld hw = new HelloWorld();
    Console.WriteLine(cs.strHelloWorld); 
  }
}

12. Using Delegates

using System;
class HelloWorld
{
  static void writeHelloWorld() {
    Console.WriteLine("HelloWorld");
  }
  static void Main() {
    SimpleDelegate d = new SimpleDelegate(writeHelloWorld);
    d();
  }
}

13. Using Attributes

#define DEBUGGING

using System;
using System.Diagnostics;

public class HelloWorld : Attribute
{
  [Conditional("DEBUGGING")]

  public void writeHelloWorld()
  {
    Console.WriteLine("Hello World");
  }

  public static void Main()
  {
    HelloWorld hw = new HelloWorld();

    hw.writeHelloWorld();
  }
}

14. Using Interfaces

using System;

interface IHelloWorld
{
  void writeHelloWorld();
}

public class HelloWorld : IHelloWorld
{
  public void writeHelloWorld()
  {
    Console.WriteLine("Hello World");
  }

  public static void Main()
  {
    HelloWorld hw = new HelloWorld();

    hw.writeHelloWorld();
  }
}

15. Dynamic Hello World

using System;
using System.Reflection;

namespace HelloWorldNS
{

  public class HelloWorld
  { 
    public string writeHelloWorld()
    {
      return "HelloWorld";
    }

    public static void Main(string[] args) 
    {
      Type hw = Type.GetType(args[0]);

      // Instantiating a class dynamically

      object[] nctorParams = new object[] {};
      object nobj = Activator.CreateInstance(hw, 
               nctorParams);

      // Invoking a method

      object[] nmthdParams = new object[] {};
      string strHelloWorld = (string) hw.InvokeMember(
              "writeHelloWorld", BindingFlags.Default | 
              BindingFlags.InvokeMethod, null, 
              nobj, nmthdParams);

      Console.WriteLine(strHelloWorld);
    }
  }
}

16. Unsafe Hello World

using System;

public class HelloWorld
{ 
  unsafe public void writeHelloWorld(char[] chrArray)
  {
    fixed(char *parr = chrArray)
    {
      char *pch = parr;
      for(int i=0; i<chrArray.Length; i++)
        Console.Write(*(pch+i));
    }
  }

  public static void Main() 
  {
    HelloWorld hw = new HelloWorld();
    char[] chrHelloWorld = new char[] 
        {'H','e','l','l','o', ' ', 'W','o','r','l','d'};
    hw.writeHelloWorld(chrHelloWorld);
  }
}

17. Using InteropServices

using System;
using System.Runtime.InteropServices;

class Class1
{
  [DllImport("kernel32")]
  private static extern int Beep(int dwFreq, int dwDuration);

  static void Main(string[] args)
  {
    Console.WriteLine("Hello World");
    Beep(1000, 2000);
  }
}

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

About the Author

Mercy Ponnupandy
Architect
United States United States
Architect / Consultant on Content Management and Cloud Computing... Artist and Author by the weekends...
Follow on   Twitter

Comments and Discussions

 
GeneralStatic Constructor and Static Function PinmemberShabbazz3-Feb-04 0:25 
GeneralCool Beans! No Java Pun Intended... Pinmemberrsyoung0122-Jan-04 10:01 
GeneralStupid and Time Wasting article PinmemberLegend Never Dies21-Jan-04 22:38 
GeneralRe: Stupid and Time Wasting article Pinmemberred_tomato14-May-04 6:58 
GeneralRe: Stupid and Time Wasting article PinmemberButch.er2-Nov-04 0:57 
Generalpretty good PinmemberTweety20-Jan-04 11:09 
GeneralNice article PinsussPer Søderlind12-Jan-04 20:20 
QuestionDoesn't this remind you of an old joke? Pinmembernsimeonov12-Jan-04 13:36 
AnswerRe: Doesn't this remind you of an old joke? PinmemberMike Kitchen13-Jan-04 22:03 
GeneralRe: Doesn't this remind you of an old joke? Pinmemberred_tomato14-May-04 6:54 
GeneralRe: Doesn't this remind you of an old joke? Pinmemberleppyr6420-Nov-07 5:33 
GeneralThis would be a great programming quiz! PineditorMarc Clifton12-Jan-04 12:57 
GeneralGreat Pinmemberhxxbin12-Jan-04 8:15 
GeneralGreat Idea Pinmemberdhirschfeld12-Jan-04 7:14 
Thank you for this nice reference document. I would love to see the same done for VB.Cool | :cool:
 
David Hirschfeld
GeneralInteresting Pinmemberdog_spawn12-Jan-04 3:07 
GeneralRe: Interesting PinmemberMike Ellison12-Jan-04 7:29 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Mobile
Web02 | 2.8.140415.2 | Last Updated 12 Jan 2004
Article Copyright 2004 by Mercy Ponnupandy
Everything else Copyright © CodeProject, 1999-2014
Terms of Use
Layout: fixed | fluid