c# INTRODUCTION - Dot Net

Overview:

• It's a programming language, offered by .NET Framework.
• It is recommended for both .NET programming beginners and .NET professionals.
• This is the mostly used language used by most of the IT companies today.
• It derives some programming features from C and C++ also.
• It is the object oriented programming language.
• The programmer, having knowledge in C and C99 can easily understand the programming in C#.

File Extension in C#

• Project File Extension: ".csproj" ( means C sharp project)
• Code File Extension : ".cs" (means c sharp)

 Sample Application Development in C#

• Launch Visual studio 2008.
• Create a new "Console Application with "Visual C#" language.
• It generate an empty "Program" class, with "Main()" method.
• To run the application simply press F5 key on the keyboard. Then the application will be executed and output will be displayed.

1.Importing section:

•     This section contain importing statement that are used to import the .NET Framework Class Library(FCL).
• This is most similar to the include statements in "C" laguage.

Syntax:

     using namespace;

Note: If the required namespace is a member of another namespace, we have specify the parent and child namespaces separated with  "." (dot).

Example

using System;
using System.IO;
using System.Data;

etc.

2. Namespace declaration

• Here, a user define namespace is to be declared.
• Rule: In .NET applications, all the classes related to the project should be declared in one namespace.

      Syntax:

          namespace namespaceName
         {
          .
          .
          }

Generally the namespace name will be same as "Project" name.

2. Class declaration:

• This is to declare the startup class of the project.
• In every .NET application (like Console and Windows Application), there should a startup class. In these applications, the startup class name should be "Program". You can't change it.
• A startup class nothing a class, which contains Main() method.

       Syntax:
         class className
         {
         .
         .
         }

3. Main() method:

• As you know already in C/C++ languages, the Main() method is the Starting Execution Point of the application.
• When the application is executed, the Main() method will be executed first.
• This method contain the main logic of the application.

     Syntax:

      class Program
     {
          static void Main(string[] args)
        {
            Console.WriteLine("Hello, World");
            Console.ReadLine();
        }
     }

Compiling and Running the Application

•  Compile : Click on "Build menu - "Build Solution". (or) press Ctrl+Shift+B.
• Run : Click on "Debug" menu - "Start Debugging".(or) Press F5 or Ctrl+F5.