C# Programming

Set up the .NET SDK, understand the CLI (dotnet new, build, run), and get comfortable with an IDE like Visual Studio or VS Code. You'll know how to create, compile, and run a C# project from scratch.

Learn value types (int, bool, double, struct) vs. reference types (string, object, class), type inference with var, and nullable value types. You'll understand how C# enforces type safety at compile time.

Master if/else, switch expressions, for/foreach/while loops, and pattern matching basics. You'll be able to write branching and iterative logic fluently.

Define methods with return types, understand ref/out/in parameters, optional parameters, and params arrays. You'll know how data flows into and out of methods.

Work with single and multi-dimensional arrays, string manipulation and interpolation, StringBuilder, and ReadOnlySpan<char> for efficient slicing. You'll handle sequential data confidently.

You can write, compile, and run basic C# programs with proper types, control flow, and methods.

Define classes, create instances, use constructors and initializers, and understand the difference between static and instance members. You'll model real-world entities in code.

Use auto-properties, getters/setters, init-only setters, and access modifiers (public, private, protected, internal) to control visibility. You'll write well-encapsulated types.

Extend classes with inheritance, override virtual methods, use abstract classes, and understand the 'is-a' relationship. You'll leverage polymorphism to write flexible code.

Define contracts with interfaces, implement multiple interfaces, and use default interface methods. You'll design code against abstractions rather than concrete types.

Choose between class, struct, record class, and record struct. Understand value equality, immutability, and when each is appropriate. You'll pick the right type shape for the job.

You can design class hierarchies, use interfaces, and choose appropriate type kinds for your domain models.

Write type-safe, reusable code with generic classes, methods, and interfaces. Apply constraints (where T : class, new(), IComparable) to express requirements. You'll eliminate duplication without sacrificing safety.

Use List<T>, Dictionary<TKey,TValue>, HashSet<T>, Queue<T>, Stack<T>, and immutable collections. You'll pick the right collection for the right job based on performance and semantics.

Understand delegate types, multicast delegates, the event keyword, and lambda expressions. You'll implement callbacks, event-driven patterns, and pass behavior as data.

Use try/catch/finally, create custom exceptions, understand exception filters, and learn when to throw vs. return error results. You'll write code that fails gracefully and communicates errors clearly.

Define enums, use switch expressions with property/positional/relational patterns, and combine patterns with logical operators. You'll write concise, expressive branching logic.

You're proficient with generics, collections, delegates, and error handling — the day-to-day tools of C# development.

Use Where, Select, OrderBy, GroupBy, and aggregate operators on collections. Understand deferred vs. immediate execution. You'll query in-memory data declaratively.

Chain complex queries, use joins, let clauses, SelectMany for flattening, and write custom extension methods that compose with LINQ. You'll handle sophisticated data transformations.

Use Func<T>/Action<T>, closures, higher-order functions, and immutable data. Understand how C# blends OOP and functional styles. You'll write concise, composable logic.

You can transform, filter, and aggregate data fluently using LINQ and functional techniques.

Write asynchronous methods with async/await, understand Task and Task<T>, and avoid common pitfalls like async void and deadlocks. You'll write non-blocking code that stays readable.

Use Task.WhenAll, Parallel.ForEachAsync, channels, and understand thread safety with lock, SemaphoreSlim, and ConcurrentDictionary. You'll safely leverage multiple cores.

Use CancellationToken to make async operations cancellable and IProgress<T> for reporting. You'll build responsive applications that users can interrupt gracefully.

You can write scalable, non-blocking code with proper cancellation and concurrency control.

Enable nullable analysis, annotate your APIs with ?, understand the null-forgiving operator, and eliminate NullReferenceExceptions at compile time. You'll write null-safe code by default.

Use Span<T> and Memory<T> for zero-allocation slicing, understand stackalloc, ArrayPool, and benchmarking with BenchmarkDotNet. You'll write high-performance code when it matters.

Read and create custom attributes, inspect types at runtime, and understand the cost of reflection. You'll build metadata-driven features and understand frameworks that use them.

Understand how source generators produce code at compile time, replacing many reflection-based patterns. You'll know when and why to use them for performance and type safety.

You understand nullable safety, performance tools, and metaprogramming techniques that power modern .NET libraries.

Use the built-in Microsoft.Extensions.DependencyInjection container, register services with appropriate lifetimes (transient, scoped, singleton), and write testable, loosely-coupled code.

Write tests with xUnit or NUnit, use Moq or NSubstitute for mocking, and practice test-driven development. You'll verify your code works and catch regressions early.

Consume and publish NuGet packages, manage dependencies, understand project files (.csproj), and use Directory.Build.props for multi-project solutions. You'll manage real-world .NET solutions.

Read and write files with StreamReader/StreamWriter, serialize data with System.Text.Json, and understand async file operations. You'll persist and exchange data in standard formats.

You have a solid, practical understanding of C# — from fundamentals through advanced features and real-world practices. You're ready to build production applications.