You know the green-on-black code flying all over the computer screens in The Matrix? Regular Expressions don't look too different. They can be really gnarly and debugging them is a pain. This is why we created a free Regular Expression tool to help learn, author, and test RegExps.
Regular Expressions are a powerful way of programmatically searching for and replacing text. They're used in a wide variety of ways. Some examples include validating inputs to ensure a user has provided a valid phone number and email address, finding all links to external websites on a web page, extracting content from one website to another, etc.
I will be using the HiFi RegExp Tool in an upcoming blog post series on "Getting Comfortable with Regular Expressions". You should subscribe to our development blog to receive updates on this series as they come.