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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?<=class=[\"'][\\w\\- :\\.]*)([\\w\\-:\\.]+)"; final String string = "<div class=\"px-4 sm:px-6 lg:px-8\">\n" + " <div class=\"sm:flex sm:items-center\">\n" + " <div class=\"sm:flex-auto\">\n" + " <h1 class=\"text-xl font-semibold text-gray-900\">Users</h1>\n" + " <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>\n" + " </div>\n" + " <div class=\"mt-4 sm:mt-0 sm:ml-16 sm:flex-none\">\n" + " <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>\n" + " </div>\n" + " </div>\n" + " <div class=\"mt-8 flex flex-col\">\n" + " <div class=\"-my-2 -mx-4 overflow-x-auto sm:-mx-6 lg:-mx-8\">\n" + " <div class=\"inline-block min-w-full py-2 align-middle\">\n" + " <div class=\"overflow-hidden shadow-sm ring-1 ring-black ring-opacity-5\">\n" + " <table class=\"min-w-full divide-y divide-gray-300\">\n" + " <thead class=\"bg-gray-50\">\n" + " <tr>\n" + " <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>\n" + " <th scope=\"col\" class=\"px-3 py-3.5 text-left text-sm font-semibold text-gray-900\">Title</th>\n" + " <th scope=\"col\" class=\"px-3 py-3.5 text-left text-sm font-semibold text-gray-900\">Email</th>\n" + " <th scope=\"col\" class=\"px-3 py-3.5 text-left text-sm font-semibold text-gray-900\">Role</th>\n" + " <th scope=\"col\" class=\"relative py-3.5 pl-3 pr-4 sm:pr-6 lg:pr-8\">\n" + " <span class=\"sr-only\">Edit</span>\n" + " </th>\n" + " </tr>\n" + " </thead>\n" + " <tbody class=\"divide-y divide-gray-200 bg-white\">\n" + " <tr>\n" + " <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>\n" + " <td class=\"whitespace-nowrap px-3 py-4 text-sm text-gray-500\">Front-end Developer</td>\n" + " <td class=\"whitespace-nowrap px-3 py-4 text-sm text-gray-500\">lindsay.walton@example.com</td>\n" + " <td class=\"whitespace-nowrap px-3 py-4 text-sm text-gray-500\">Member</td>\n" + " <td class=\"relative whitespace-nowrap py-4 pl-3 pr-4 text-right text-sm font-medium sm:pr-6 lg:pr-8\">\n" + " <a href=\"#\" class=\"text-indigo-600 hover:text-indigo-900\">Edit<span class=\"sr-only\">, Lindsay Walton</span></a>\n" + " </td>\n" + " </tr>\n\n" + " <!-- More people... -->\n" + " </tbody>\n" + " </table>\n" + " </div>\n" + " </div>\n" + " </div>\n" + " </div>\n" + "</div>"; final String subst = ""; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + 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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html