A regular expression … is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. “find and replace”-like operations.



  • Rubular
    • “Rubular is a Ruby-based regular expression editor”
  • Pythex
    • “pythex is a quick way to test your Python regular expressions”
  • RegExr
    • “RegExr is an online tool to learn, build, & test Regular Expressions”