Introducing C# 10: Extended property patterns

Introduction

C# 8 has introduced a new pattern: Property pattern. This pattern enables you to match on properties of the object examined, if you missed that feature, here is the Microsoft documentation here: Property pattern. C# 10 improves that pattern by simplifying access to nested properties. In the article I’ll show what it is.

Example

The following code sample shows a C# 8 tax calculator, which involves an object named CalculateTax and its nested property named ProvinceOrStateTaxProperty which is itself an object:

The syntax to access the nested property is a bit verbose:

{ ProvinceTaxProperty: { ProvinceOrState: "Value" } }

C# 10 fixes that and allows to access directly the nested property by a dot:

Much more practical isn’t it ? 😉