14. Modern C# Next

Modern C# has evolved well beyond its Java-inspired origins. This chapter covers language features that make C# code more expressive, concise, and readable — without requiring a deep class hierarchy.

Why these features matter

These five features appear constantly in modern C# codebases:

• Pattern matching — replaces chains of if/else and is/as casts with clear, structural dispatch

• Record types — eliminate boilerplate for data-carrying types; you have been using them since Ch.9 — now we name what they give you

• Nullable operators — make null-handling explicit and safe; ?., ??, ??= are in every real codebase

• Generics — explain the <T> you have been using in List<T> and LINQ; writing generic methods and classes yourself reduces duplication

• Async/await — keep programs responsive while waiting for files, networks, or databases without writing complex threading code

Learning goals

By the end of this chapter, you should be able to:

• use switch expressions and is patterns to match on type and structure

• explain what record adds over class: value equality, with, deconstruction, and init-only properties

• choose between record, class, and struct for a given design

• handle null safely using ?., ??, ??=, and nullable annotations

• write and read generic methods and classes that use <T> and type constraints

• call async methods using await and understand when asynchrony is appropriate

Chapter flow

• 14.1. Pattern Matching
• 14.2. Record Types
• 14.3. Nullable Types and Null Operators
• 14.4. Generics
• 14.5. Async and Await