Regular Expressions: A Practical JavaScript Guide

Regular expressions are powerful for text matching and manipulation. This guide covers practical patterns for common tasks.

Basic Syntax#

Common Patterns#

Email Validation#

URL Validation#

Phone Numbers#

Password Validation#

Capturing Groups#

String Methods#

Replace with Functions#

Lookahead and Lookbehind#

Practical Examples#

Extract All URLs#

Sanitize Input#

Parse CSV Line#

Highlight Search Terms#

Performance Tips#

Regular expressions are powerful but can be hard to read. Add comments for complex patterns and consider named groups for clarity.