Introduction

A strongly-typed, OOP language created by Microsoft.

Runs on .NET (runtime + libraries)
Compiled → high performance
Very popular for:
- Web APIs (ASP.NET Core)
- Enterprise systems
- Cloud & microservices
- Desktop apps
- Games (Unity)

Flow

C# code → compiled → IL (Intermediate Language) → JIT → native machine code

Naming convention

Thing	Style	Example
Class	PascalCase	`UserService`
Method	PascalCase	`CreateUser()`
Public property	PascalCase	`UserName`
Local variable	camelCase	`userName`
Private field	`_camelCase`	`_userName`

`var`

Type inferred at compile time
Strongly typed
Use when type is obvious

// when type is obvious
var x = 10;        // int
var y = "hello";   // string
var user = new User();
var list = new List<int>();

// when type is unclear, DONT use
var x = GetData(); // what is x??
public var GetUser() // ❌ what will return??