Introduction to C#

Instructor: Venkat

Overview

• This is Part 1 of the C# introduction module.
• Focus will be on the basic structure of a C# program and the concept of namespaces, particularly the main method.

Setting Up Visual Studio

1. Launch Visual Studio 2010.
2. Create a new project:
   • Go to File > New Project.
   • Choose C# as the programming language.
   • Select Console Application type.
   • Name the project "Introduction to C#" and save it in the C Drive.

Basic C# Program Structure

• Aim: Print a message to the console.
• The console refers to the command prompt window, accessed by typing CMD in the run dialog.

Writing the Program

• The program should consist of minimal code to achieve the desired output.
• Remove unnecessary namespace declarations and parameters in the main method.
• Use the Console class from the .NET Framework to display messages.
• Key method: WriteLine() to print messages.
  • Example: Console.WriteLine("Welcome to C# training");
• To run the program, press Ctrl + F5.

Understanding Namespaces

• Namespace Declaration:
  • Introduces a namespace to use classes within it.
  • Example: using System;
• A namespace is a collection of classes, interfaces, structures, enums, and delegates.
• The purpose of namespaces: Organizing code.
• Without the namespace declaration, you must use the fully qualified name for classes.
• Example: Fully qualified name for the Console class is System.Console.

Important Concepts

Class

• All C# code must reside within a class.
• Discussed types of classes: static and instance classes.

Main Method

• The main method serves as the entry point for program execution.
• Only one main method can exist per application.
• Example of main method syntax:

• If there are multiple methods named "main", only the correctly defined main method will run (the one without a suffix).

Execution Flow

• Execution starts at the main method and ends when the program reaches the end of the method.
• To call another method within the main method, it can be done directly, ensuring both messages are printed.

Summary

• Key components of a simple C# program:
  • Namespace declaration.
  • Class definition.
  • Main method as the entry point of the application.
• Importance of using namespaces for code organization.

Additional Resources

• Check the website for more resources.
• For interview questions, visit the provided link.