Introducing C# 9: Improved pattern matching

Introduction

Pattern matching has been introduced in C# 6 and has well evolved since. The latest improvement was pretty interesting on C# 8 which has been released last year. If you missed pattern matching improvements on C# 8 , here is a nice article from Miguel Bernard (@MiguelBernard88): https://blog.miguelbernard.com/pattern-matching-in-csharp/. If you have missed all new features in C# 8, you can read also his great serie here: https://blog.miguelbernard.com/csharp-8-0-new-features/.

In this article I will show you all the great new features of pattern matching.

Relational patterns

C# 9 allows you to use relational pattern which enables the use of <, >, <= and >= in patterns like this:

Logical patterns

C# 9 lets you use logical operators like ‘and’, ‘or’ and ‘not’ , they can even be combined with relational patterns like this:

Not patterns

‘not‘ logical operator can also be used in a if statement (it works also with a ternary statement), like this:

Simple type pattern

Another nice improvement of C# 9: Simple type pattern. When a type matches, the underscore symbol _ (commonly named discard parameter) can be omitted, thats makes the syntax lighter:

Hope you like this bunch of improvements 😉