Resources

Tools

• RegExr - A free online tool for learning, building, and testing regular expressions

Reference material

• Learn regex the easy way - A more in-depth guide to using regular expressions (intermediate level)
• RegExp - JavaScript regular expression reference from Mozilla Developer Network
• Regular Expressions - chapter on regex from the book Eloquent JavaScript
• JavaScript Regular Expression Enlightenment - A detailed guide to regular expressions (advanced level)

Character lists

• ASCII - Wikipedia
• Unicode Character Table
• Emoji unicode characters for use on the web

Challenges

• Regex Crossword - Find the character that matches regex clues for each square in the puzzle
• Regex Golf - Try to match all the words in one column but not the other
• RegexPlay - Test your regex skills!
• Regular expression exercises - Sketch Engine

---