Quickly familiarize yourself with regular expressions in C#, and learn how to use .NET regular expressions to implement powerful text pattern matching.

Regular expressions provide an extremely powerful method for pattern matching with strings. They are very useful for parsing information like dates, phone numbers, or zip codes from important text files, such as code files, log files, spreadsheets, or documents. The course discusses everyday use cases of regular expressions, e.g., data validation, information extraction, pattern matching, and search and replace.

This course will teach you the core concepts of pattern matching, character classes, special and meta characters, and quantifiers. You will also learn conditional regular expressions including lookahead and lookbehind assertions. You will also learn the APIs used in C# for regular expressions with hands-on code widgets. 

This course will teach you how to perform pattern matching with a regular expression using String and Regex APIs for the above-mentioned practical use cases in C#.

Tarun Telang

Tarun Telang is a passionate software engineer, leader, architect, author, and active contributor in various online technical forums.

C# and Microsoft Expert

Working with Regular Expressions in C#

## Components of a regular expression

Below are the basic components that make up a regular expression:

**Characters** : These appear in the string being matched. For example, the characters `a` and `b` appear in the string `abc`.

**Metacharacters** : These have a special meaning in a regular expression. For example, the metacharacter `.` (dot) matches any character.

**Quantifiers** : These specify how many of the previous characters, or groups of characters, must be present. For example, the quantifier `*` (asterisk) means “zero or more occurrences.”

**Regular Expression Options** : These change the way a regular expression is matched. For example, the `i` (ignore case) or `RegexOptions.IgnoreCase` option means that the case should be ignored when matching.


# Components of a regular expression

Below are the basic components that make up a regular expression:

**Characters** : These appear in the string being matched. For example, the characters `a` and `b` appear in the string `abc`.

**Metacharacters** : These have a special meaning in a regular expression. For example, the metacharacter `.` (dot) matches any character.

**Quantifiers** : These specify how many of the previous characters, or groups of characters, must be present. For example, the quantifier `*` (asterisk) means “zero or more occurrences.”

**Regular Expression Options** : These change the way a regular expression is matched. For example, the `i` (ignore case) or `RegexOptions.IgnoreCase` option means that the case should be ignored when matching.


Learn about the components of regular expressions and the art of desired outputs from regular expressions.

Introduction

Building Blocks of .NET Regular Expressions

Advanced Concepts

Course Wrap Up

Formatting the Output of Regular Expressions

Components of a regular expression