Introduction
C# 14 introduces extension members, one of the most impactful changes since LINQ. With this feature, you can extend types you don’t own with properties, methods, indexers, and even static members.
In this article, you’ll learn:
What extension members are in C# 14
The difference between extension members and extension methods
How to implement extension properties and methods
The limitations and pitfalls you should know
Best practices and real-world use cases
1. What Are Extension Members in C# 14?
Extension members build on extension methods by allowing developers to add:
Instance members (properties, methods, indexers)
Static members (factories, constants, operators)
They are declared inside a static class using the new extension block syntax.