Program Structure

A C# program consists of the following parts:

• Namespace declaration

• A class

• Class methods

• Class attributes

• A Main method

• Statements and Expressions

• Comments

Let us look at a simple code that prints the words “Hello World”:

using System;
namespace HelloWorldApplication
{
   class HelloWorld
   {
       static void Main(string[] args)
       {
           /* my first program in C# */
           Console.WriteLine("Hello World");
       }
    }
}

let’s break down each line of the C# code:

1. using System;:
   This line tells the compiler to include the System namespace, which provides fundamental functionality for C# programs.

2. namespace HelloWorldApplication:
   This line defines a namespace named “HelloWorldApplication” to organize the code.
   It acts as a container for classes and helps prevent naming conflicts.

3. class HelloWorld:
   This line declares a class named “HelloWorld” within the “HelloWorldApplication” namespace.
   Classes are used to define objects and their behavior.

4. static void Main(string[] args):
   This line declares a static method named “Main” with a parameter named “args” of type string array.
   The “Main” method is the entry point of the program, and it is automatically executed when the program starts.

5. /* my first program in C# */:
   This line is a comment. It is ignored by the compiler and is used to provide notes or explanations to the developers.

6. Console.WriteLine("Hello World");:
   This line outputs the string “Hello World” to the console. It displays the message on the screen.