Category: C#

Use File.ReadAllText/WriteAllText and stream-based APIs for large files.

Serialize/deserialize JSON with System.Text.Json (or Newtonsoft.Json).

Convert objects to JSON/XML/binary formats and back safely.

Use DateTime, DateTimeOffset, and TimeProvider patterns carefully.

Write SQL-like query expressions with from/where/select.

Write concise functions with => for LINQ, events, and APIs.

Define type-safe method references with delegates / Func / Action.

Publish notifications with event keyword and EventHandler patterns.

Understand anonymous methods as the predecessor to lambdas.

Add methods to existing types via static extensions.