C#

C# fundamentals in plain English — types, collections, LINQ and the language features that make everyday code shorter.

16 guides

C# Performance Optimization

Profiling before guessing, then the fixes that pay: allocations, LINQ in hot paths, string building, Span, async correctness and database queries.

Nov 7, 2026 5 min read

Introduction to C#

What C# is, what .NET provides, where the language is used, and your first program — plus how it compares with Java,…

Nov 2, 2026 4 min read

C# Events and Delegates

What a delegate is, how events build on them, Action and Func, and the two mistakes that cause memory leaks and null…

Nov 1, 2026 5 min read

C# Design Patterns

The design patterns that earn their place in C#: strategy, factory, repository, decorator, observer and options — with the language features that…

Oct 31, 2026 4 min read

FileSystemWatcher Not Working in C#

Events that never fire, fire twice, or stop after a while. The causes: it fell out of scope, EnableRaisingEvents is false, the…

Oct 26, 2026 5 min read

Distinct() Not Working on Objects in C#

Distinct removes duplicates by equality, and for classes equality means the same instance. Three fixes: DistinctBy, a record, or IEquatable, and which…

Oct 26, 2026 3 min read

C# 14 Extension Members Explained

Extension members let you add properties, static members and operators to types you do not own, not just methods. The new extension…

Oct 25, 2026 4 min read

C# Generics

Generic classes, methods and constraints in C#, why the generic List beats ArrayList, and the variance keywords in and out explained plainly.

Oct 24, 2026 5 min read

C# Testing

Writing unit tests in C# with xUnit: arrange-act-assert, parameterised tests, mocking dependencies, and what is actually worth testing.

Oct 22, 2026 4 min read

ASP.NET Core Error Handling: Middleware, ProblemDetails and Best Practices

Unhandled exceptions should become consistent, safe JSON responses. The built-in exception handler, ProblemDetails, custom exception mapping and what to log, with working…

Oct 18, 2026 4 min read

C# Deployment

How to publish a .NET application: framework-dependent versus self-contained builds, single-file output, trimming, Docker and configuration for production.

Oct 17, 2026 4 min read

C# Basics

The core of C# in one page: types, variables, conditions, loops, methods, collections and classes, with the compiler errors beginners meet.

Oct 13, 2026 5 min read

Where to go next

Programming Basics The ideas every language shares — variables, loops, functions and how a program actually runs. 17 guides Python Plain-English Python guides, from your first line of code to small programs that do real work. 72 guides JavaScript How JavaScript works in the browser, explained with short examples you can paste and run. 32 guides

Keep going — pick your next guide

The fastest way to improve is to read one guide, then build the thing it describes. Start with the basics, or jump straight to a project.

Start with the basics See beginner projects