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

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 = "const.*=.*\\{+$"; final String string = "exports.async_createUser = async (user, required) => {\n" + "exports.async_createUser = async (user, required) => \n\n" + "const test = function(a,b) => {\n" + "const test = (a,b) => {\n" + "const test = a => {\n" + "const async_getInfAuthToken = async () => {\n" + "const convertFromStateABV = async abv => {\n" + "const customField = infUser.custom_fields.filter(index => {\n" + "const thing = new user({\n" + "// const thing = new user({\n" + "// inf.updateWedding(weddingId);\n" + "inf.setMilestoneDate(req.user, 8);\n" + "}); //User email >> Spouse email (42)\n" + "exports.infCreate = function(req, callback) {\n" + "const user = await User.findOne({ _id: wedding.users[numUser] });\n\n" + "const test = function(a,b) \n" + "const i = require(./stuff)\n" + "// const userC = require(\"./users\");\n\n" + "const User = require(\"./../models/user\");\n" + "const Utils = require(\"./../utils\");\n" + "const userC = require(\"./users\");\n" + "const Wedding = require(\"./../models/wedding\");\n" + "const config = require(\"./../config\");\n" + "const request = require(\"request-promise\");\n" + "const sms = require(\"./smss\");\n" + "const email = require(\"./emails\");\n" + "const contacts = require(\"./contacts\");\n\n\n" + "\"error [inf.getNumberOfContactsFromWeddingID] : \" + //\n" + "inf.applyTagToUser(userList[i].inf_id, [ //\n" + "// inf.setMilestoneDate(userList[i], 8);\n" + "inf.applyTagToUser(u.inf_id, [564]); //[Fulfillment _ 110 _ DLY _ LM _ WT - couples _ v01 _ START]\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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