Pattern Matching with Regular Expressions

Learn about regular expressions to validate user input, understand their syntax, and efficiently use them for tasks like splitting complex comma-separated strings.

We'll cover the following

Checking for digits entered as text
- Try it yourself
Regular expression performance improvements
- .NET 5 and later
- .NET 7 and later
Understanding the syntax of a regular expression
Examples of regular expressions
Splitting a complex comma-separated string
- Try it yourself

Regular expressions are useful for validating input from the user. They are very powerful and can get very complicated. Almost all programming languages support regular expressions and use a common set of special characters to define them. Let’s try out some example regular expressions:

Step 1: Use your preferred code editor to add a new Console App or console project named WorkingWithRegularExpressions to the Chapter08 solution or workspace:

In Visual Studio Code, select WorkingWithRegularExpressions as the active OmniSharp project.

Step 2: In Program.cs, delete the existing statements, and then import the following namespace:

Get hands-on with 1400+ tech skills courses.

Introduction

Hello, C#! Welcome, .NET!

Speaking C#

Controlling Flow, Converting Types, and Handling Exception

Writing, Debugging, and Testing Functions

Building Your Own Types with Object-Oriented Programming

Implementing Interfaces and Inheriting Classes

Packaging and Distributing .NET Types

Working with Common .NET Types

Working with Files, Streams, and Serialization

Working with Data Using Entity Framework Core

Querying and Manipulating Data Using LINQ

Introducing Web Development Using ASP.NET Core

Building Websites Using ASP.NET Core Razor Pages

Building Websites Using the Model-View-Controller Pattern

Building and Consuming Web Services

Building User Interfaces Using Blazor

Conclusion

Pattern Matching with Regular Expressions