C # Program Structure

C # Hello World instance

A C # program mainly includes the following sections:

• namespace declaration (Namespace declaration)
• A class
• Class method
• Class Property
• A Main method
• Statements (statements) & Expressions (Expressions)
• Comments

Let's look at a simple code that can print out "Hello World":

Using System;Namespace Helloworldapplication{ Class HelloWorld { static  main (string[]< Span class= "PLN" > Args)  {/* my first C # program */ console. Writeline "Hello World" console. Readkey} }}    /span>                

When the above code is compiled and executed, it produces the following results:

Hello World

Let's take a look at the various parts of the above program:

• The first line of the program using System; -the using keyword is used to include the system namespace in your program. A program generally has multiple using statements.
• The next line is the namespace declaration. A namespace is a series of classes. The helloworldapplication namespace contains class HelloWorld.
• The next line is the class declaration. Class HelloWorld contains the data and method declarations used by the program. Class generally contains multiple methods. Method defines the behavior of the class. Here, theHelloWorld class has only one Main method.
• The next line defines the Main method, which is the entry point for all C # programs. The Main method describes what actions the class will do when it executes.
• The next line of/*...*/will be ignored by the compiler, and it will add additional annotations to the program.
• The Main method uses the statement Console.WriteLine ("Hello World") and specifies its behavior.

  WriteLine is a method that defines the Console class in the System namespace. The statement displays the message "Hello, world!" on the screen.

• The last line Console.readkey (); is for vs.net users. This allows the program to wait for a keystroke action to prevent the screen from running and shutting down quickly when the program starts from Visual Studio. NET.

The following points are worth noting:

• C # is case-sensitive.
• All statements and expressions must end with a semicolon (;).
• The execution of the program starts with the Main method.
• Unlike Java, a file name can be different from the name of a class.

Compiling & executing C # programs

If you are using Visual Studio.NET to compile and execute a C # program, follow these steps:

• Start Visual Studio.
• On the menu bar, select Project, File, New.
• Select Visual C # from the template, and then select Windows.
• Select Console Application.
• Make a name for your project, and then click the OK button.
• The new project appears in Solution Explorer (Solution Explorer).
• Write code in the Code Editor.
• Click the Run button or press the F5 key to run the program. A command Prompt window will appear (commands Prompt windows) to display Hello world.

You can also use the command line instead of the Visual Studio IDE to compile C # programs:

• Open a text editor and add the code mentioned above.
• Save the file as HelloWorld.cs.
• Open the command prompt tool and navigate to the directory where the file is saved.
• Type csc helloworld.cs and press the ENTER key to compile the code.
• If the code has no errors, the command prompt goes to the next line and generates the helloworld.exe executable file.
• Next, type HelloWorld to execute the program.
• You will see "Hello World" printed on the screen.

C # Program Structure