C# Code Typing

Null Operators

?. ?? ??= and the null-forgiving bang

Generics & Constraints

Angle brackets, where clauses, and nested type arguments

Async Punctuation

async Task<T>, await using, await foreach, and ConfigureAwait

Pattern Matching

Property patterns, switch arms, tuples, and out var

Checkpoint: Symbol Fluency

Every C# glyph cluster from this module in one longer drill

Keywords

Modern .NET keywords

Declarations

Records, nullable types, and properties

Modifiers & Members

sealed, required, virtual, override, and init accessors

Query Syntax

from, where, let, group by into, orderby, select

Idiomatic Patterns

LINQ and modern C# one-liners

Collection Expressions

C# 12 literals, spreads, and dictionary initializers

Checkpoint: Keywords & Idioms

An interface, a primary constructor, and a static helper in one pass

Control Flow

Pattern matching, loops, and switches

Functions & Methods

Async methods and expression bodies

Records & With Expressions

Non-destructive mutation and positional deconstruction

Exceptions & Filters

A custom exception plus catch ... when guards

Injected Service

A primary-constructor service with logging and a guard clause

Realistic Snippet

LINQ report over a list of records

Async Streams

An IAsyncEnumerable producer consumed with await foreach

Checkpoint: Real Snippets

Records, a join, and a grouped report typed end to end

Speed Run: Channel Pipeline

A bounded producer and consumer typed without stopping

Speed Run: Retry With Backoff

A generic retry helper with doubling delays at full pace

Speed Run: Custom Comparer

IComparer<T> with null handling driving a sorted queue

Speed Run: Minimal API

Endpoint registration blocks with route constraints

Speed Run: xUnit Tests

Fact and Theory attributes with InlineData rows

Checkpoint: Sustained Speed

A latency percentile report typed in one continuous run

Assessment Sim 1: Word Histogram

A complete file-to-frequency program with LINQ and GroupBy

Assessment Sim 2: RPN Calculator

A Stack<double> evaluator with every error path wired up

Assessment Sim 3: Inventory Ledger

A stock-movement program that rejects oversell

Assessment Sim 4: CSV To Records

Parse, group, and print a ranked table with aligned columns

Checkpoint: C# Mastery Final

A resilient async API client -- the course's graded final