: Enables adding new methods to existing classes without modifying their original source code.

C# 3.0, released in 2007, was a monumental update that transformed the language into a hybrid of Object-Oriented and Functional programming. It introduced , allowing you to write SQL-like queries directly inside your C# code to manipulate data in arrays, XML, and databases . 🚀 Key C# 3.0 Features at a Glance

: Simplified syntax for initializing a new object or list and setting its properties in one step. 📘 Recommended Learning Resources

: Concise inline functions (e.g., x => x * x ) that replaced the more verbose anonymous methods from C# 2.0.

: Let you create temporary objects on the fly without declaring a formal class.

If you are looking to dive deeper into these classic features, these authoritative guides are highly recommended: The history of C# | Microsoft Learn

: A shorthand for defining properties without manually creating private backing fields.