Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

re = /(?<=class=["'][\w\- :\.]*)([\w\-:\.]+)/m str = '<div class="px-4 sm:px-6 lg:px-8"> <div class="sm:flex sm:items-center"> <div class="sm:flex-auto"> <h1 class="text-xl font-semibold text-gray-900">Users</h1> <p class="mt-2 text-sm text-gray-700">A list of all the users in your account including their name, title, email and role.</p> </div> <div class="mt-4 sm:mt-0 sm:ml-16 sm:flex-none"> <button type="button" class="inline-flex items-center justify-center rounded-md border border-transparent bg-indigo-600 px-4 py-2 text-sm font-medium text-white shadow-sm hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-2 sm:w-auto">Add user</button> </div> </div> <div class="mt-8 flex flex-col"> <div class="-my-2 -mx-4 overflow-x-auto sm:-mx-6 lg:-mx-8"> <div class="inline-block min-w-full py-2 align-middle"> <div class="overflow-hidden shadow-sm ring-1 ring-black ring-opacity-5"> <table class="min-w-full divide-y divide-gray-300"> <thead class="bg-gray-50"> <tr> <th scope="col" class="py-3.5 pl-4 pr-3 text-left text-sm font-semibold text-gray-900 sm:pl-6 lg:pl-8">Name</th> <th scope="col" class="px-3 py-3.5 text-left text-sm font-semibold text-gray-900">Title</th> <th scope="col" class="px-3 py-3.5 text-left text-sm font-semibold text-gray-900">Email</th> <th scope="col" class="px-3 py-3.5 text-left text-sm font-semibold text-gray-900">Role</th> <th scope="col" class="relative py-3.5 pl-3 pr-4 sm:pr-6 lg:pr-8"> <span class="sr-only">Edit</span> </th> </tr> </thead> <tbody class="divide-y divide-gray-200 bg-white"> <tr> <td class="whitespace-nowrap py-4 pl-4 pr-3 text-sm font-medium text-gray-900 sm:pl-6 lg:pl-8">Lindsay Walton</td> <td class="whitespace-nowrap px-3 py-4 text-sm text-gray-500">Front-end Developer</td> <td class="whitespace-nowrap px-3 py-4 text-sm text-gray-500">lindsay.walton@example.com</td> <td class="whitespace-nowrap px-3 py-4 text-sm text-gray-500">Member</td> <td class="relative whitespace-nowrap py-4 pl-3 pr-4 text-right text-sm font-medium sm:pr-6 lg:pr-8"> <a href="#" class="text-indigo-600 hover:text-indigo-900">Edit<span class="sr-only">, Lindsay Walton</span></a> </td> </tr> <!-- More people... --> </tbody> </table> </div> </div> </div> </div> </div>' subst = '' result = str.gsub(re, subst) # Print the result of the substitution puts result

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html