Regular Expressions are an essential tool for any developer but they're a source of real terror for many web designers. A Regular Expression is a pattern to match strings of text, using RegExp you can save a lot of time and code lines.
RegExplained Online Tool
You can test the expressions that you've learnt in the video with this online web application created by Lea. You’ll be familiar with the most commonly used syntax in regular expressions.
Introducing Regular Expressions Book
Another great resource to start with regular expressions is this easy-to-follow guide. You’ll learn with examples how to match words, characters, and patterns. You will understand how save time using RegExp in various programming languages.