Introduction To C#

C# is a modern, object-oriented programming language developed by Microsoft in 2000 as part of the .NET framework initiative. It was designed to be simple, powerful, and versatile, making it a popular choice for building desktop applications, web applications, mobile apps, cloud-based services, and even games using the Unity engine.

Why Learn C#?

C# strikes a balance between performance, productivity, and readability. It is widely used in enterprise environments, game development, and modern cross-platform applications. With the support of .NET (including .NET Core and the latest .NET 9), C# runs on Windows, macOS, and Linux, giving developers flexibility and scalability.

Key Features of C#:

1. Object-Oriented – Supports classes, objects, inheritance, polymorphism, and encapsulation.

2. Strongly Typed – Variables must have a defined type, reducing runtime errors.

3. Cross-Platform – Works with .NET to run on different operating systems.

4. Rich Standard Library – Provides built-in functionality for file handling, networking, security, and more.

5. Memory Management – Automatic garbage collection reduces memory leaks.

6. Modern Features – Includes async/await, LINQ (Language Integrated Query), pattern matching, and lambda expressions.

Basic C# Syntax

C# code is organized into namespaces and classes. The entry point of every C# program is the Main method.

Example: A Simple "Hello, World!" Program

using System;
namespace HelloWorldApp
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Hello, World!");
}
}
}

Explanation:

• using System; → Imports the System namespace, which contains basic classes like Console.

• namespace HelloWorldApp → Defines a namespace to group related code.

• class Program → Declares a class named Program.

• static void Main(string[] args) → The program’s entry point.

Common Data Types in C

• int → Represents integers (example: 42).

• double → Represents floating-point numbers (example: 3.14).

• char → Represents a single character (example: 'A').

• string → Represents text (example: "Hello").

• bool → Represents true/false values.

Example:

int age = 25;
string name = "Alice";
bool isStudent = true;
double score = 95.6;

Console.WriteLine("Name: " + name + ", Age: " + age + ", Score: " + score + ", Student: " + isStudent);

What Can You Build with C#?

• Web Applications using ASP.NET Core

• Mobile Apps with Xamarin or .NET MAUI

• Desktop Apps with WPF or WinForms

• Games with Unity Engine

• Cloud Services on Microsoft Azure

• APIs and Libraries for business and enterprise solutions