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C # program structure

Before we learn the basic building blocks of C # programming language, let us look at a minimum of C # program structure, to serve as reference for the next chapter.

C # Hello World Examples

A C # program includes the following components:

  • Namespace declaration (Namespace declaration)
  • A class
  • Class Methods
  • Class Properties
  • A Main method
  • Statements (Statements) & Expressions (Expressions)
  • Note

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

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

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

Hello World

Let's look at each part of the above program:

  • The first line of the programusing System; - usingkeywords used to contain theSystemnamespace in the program.Using a procedure generally have multiple statements.
  • The next line is anamespace declaration.Anamespace is a series of classes.HelloWorldApplicationnamespace contains classesHelloWorld.
  • The next line is the class declaration.HelloWorldclass contains data declarations and method used by the program. Class typically contain multiple methods. The method defines a class act.Here,HelloWorld class has only one Main method.
  • The next line defines theMain method is that all C # program entry point.Main method Description When performing class action will do.
  • /*...*/ Next line will be ignored by the compiler, and it will add extracomments in the program.
  • Main method statementConsole.WriteLine ( "Hello World"); specifies its behavior.

    WriteLineis a methodof the Consoleclass in theSystemnamespace definition. This statement will be displayed on the screen message "Hello, World!".

  • The last lineConsole.ReadKey (); for VS.NET users.This makes the program will wait for a key operation, when prevented from Visual Studio .NET startup screen and quickly run off.

The following points are noteworthy:

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

Compile & execute C # program

If you are using Visual Studio.Net C # compile and execute the program, please follow the steps below:

  • Start Visual Studio.
  • On the menu bar, select File -> New -> Project.
  • Select Visual C # from the template, and then select Windows.
  • Select Console Application.
  • To develop a name for your project, and then click the OK button.
  • The new project appears in Solution Explorer (Solution Explorer) in.
  • Write code in the code editor (Code Editor) in.
  • Click the Run button or press the F5 key to run the program. There will be a command prompt window (Command Prompt window), displays Hello World.

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

  • Open a text editor, add the code mentioned above.
  • Save the file ashelloworld.cs.
  • Open a command prompt tool, navigate to the directory to save the file.
  • Typecsc helloworld.cs and press the enter key to compile the code.
  • If the code is not an error, the command prompt enter the next line, and generateshelloworld.exe executable file.
  • Next, typehelloworld to execute the program.
  • You will see "Hello World" printed on the screen.