Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

r"
"
gm

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^\s+\""#{prefix}\.(.+)\"":"; string input = @"""use strict"" define -> launchOptions = (prefix) -> options = ""#{prefix}.businessCredits.businessBudgetFacility"": functionDetails: functionId : ""be.kbc.businessCredits.businessBudgetFacility"", mode: ""create"" ""#{prefix}.businessCredits.taxPrepaymentPlan"": functionDetails: functionId : ""be.kbc.businessCredits.taxPrepaymentPlan"", mode: ""create"" ""#{prefix}.credits.privateCreditCardRequest.update"": functionDetails: functionId : ""be.kbc.credits.privateCreditCardRequest"", mode: ""update"" ""#{prefix}.credits.homeAtOnce"": functionDetails: functionId : ""be.kbc.credits.homeAtOnce"", mode: ""createRequest"" ""#{prefix}.credits.homeAtOnce.detailRequest"": functionDetails: functionId : ""be.kbc.credits.homeAtOnce"", mode: ""detailRequest"" ""#{prefix}.credits.homeAtOnce.editRequest"": functionDetails: functionId : ""be.kbc.credits.homeAtOnce"", mode: ""editRequest"" ""#{prefix}.credits.homeAtOnce.updateRequest"": functionDetails: functionId : ""be.kbc.credits.homeAtOnce"", mode: ""updateRequest"" ""#{prefix}.credits.budgetfacilitylight"": functionDetails: functionId : ""be.kbc.credits.budgetFacilityLight"", mode: ""create"" ""#{prefix}.credits.loaRequest"": functionDetails: functionId : ""be.kbc.credits.loaRequest"", mode: ""create"" ""#{prefix}.credits.loaRequest.update"": functionDetails: functionId : ""be.kbc.credits.loaRequest"", mode: ""update"" ""#{prefix}.doccle.doccleAccount"": functionDetails: functionId : ""be.kbc.doccle.doccleAccount"", mode: ""create"" ""#{prefix}.esigning.esigning"": functionDetails: functionId : ""be.kbc.esigning.esigning"", mode: ""create"" ""#{prefix}.esigning.esigning.createBundle"": functionDetails: functionId : ""be.kbc.esigning.esigning"", mode: ""createBundle"" ""#{prefix}.home.dinoHomeInsurance"": functionDetails: functionId : ""be.kbc.home.dinoHomeInsurance"", mode: ""create"" ""#{prefix}.home.energyRenovationAdvice"": functionDetails: functionId : ""be.kbc.home.era"", mode: ""create"" ""#{prefix}.insurances.smallProducts"": functionDetails: functionId : ""be.kbc.insurances.smallProducts"", mode: ""create"" ""#{prefix}.insurances.smallproducts.external"": functionDetails: functionId : ""be.kbc.insurances.smallProducts"", mode: ""create"" ""#{prefix}.insurances.insurancesUpsell"": functionDetails: functionId : ""be.kbc.insurances.insurancesUpsell"", mode: ""create"" ""#{prefix}.investments.buycooperativeshares"": functionDetails: functionId : ""be.kbc.investments.buyCooperativeShares"", mode: ""create"" ""#{prefix}.savings.acceptSavingsAccount"": functionDetails: functionId : ""be.kbc.savings.acceptSavingsAccount"", mode: ""create"" ""#{prefix}.savings.manageAccountInsurance"": functionDetails: functionId : ""be.kbc.savings.manageAccountInsurance"", mode: ""create"" ""#{prefix}.savings.manageAccountInsurance.delete"": functionDetails: functionId : ""be.kbc.savings.manageAccountInsurance"", mode: ""delete"" ""#{prefix}.savings.openSavingsAccount"": functionDetails: functionId : ""be.kbc.savings.openSavingsAccount"", mode: ""create"" ""#{prefix}.savings.settleSavingsAccount"": functionDetails: functionId : ""be.kbc.savings.settleSavingsAccount"", mode: ""create"" ""#{prefix}.payments.businessAccountRequest"": functionDetails: functionId : ""be.kbc.payments.businessAccountRequest"", mode: ""create"" ""#{prefix}.payments.cardPhoto"": functionDetails: functionId : ""be.kbc.payments.cardPhoto"", mode: ""create"" ""#{prefix}.payments.preaccountrequest"": functionDetails: functionId : ""be.kbc.payments.preAccountRequest"", mode: ""create"" ""#{prefix}.payments.privateAccountRequest"": functionDetails: functionId : ""be.kbc.payments.privateAccountRequest"", mode: ""create"" ""#{prefix}.payments.businessCreditCardRequest"": functionDetails: functionId : ""be.kbc.payments.businessCreditCardRequest"", mode: ""create"" ""#{prefix}.payments.preCardRequest"": functionDetails: functionId : ""be.kbc.payments.preCardRequest"", mode: ""create"" ""#{prefix}.payments.preCardRequest.createReplacement"": functionDetails: functionId : ""be.kbc.payments.preCardRequest"", mode: ""createReplacement"" ""#{prefix}.vehicle.dinoCarInsurance"": functionDetails: functionId : ""be.kbc.vehicle.dinoCarInsurance"", mode: ""create"" ""#{prefix}.vehicle.privateLease"": functionDetails: functionId : ""be.kbc.vehicle.privateLease"", mode: ""create"" ""#{prefix}.vehicle.privateLease.update"": functionDetails: functionId : ""be.kbc.vehicle.privateLease"", mode: ""update"" # Note: the deeplinks below are for local development testing only, the won't be available in the pillars # coffeelint: disable=no_backticks `//>>includeStart(""local"", pragmas.local)` options[""#{prefix}.credits.genericRequest""] = functionDetails: functionId : ""be.kbc.credits.genericRequest"", mode: ""create"" options[""#{prefix}.credits.genericRequest.continue""] = functionDetails: functionId : ""be.kbc.credits.genericRequest"", mode: ""continue"" `//>>includeEnd(""local"")` return options return launchOptions "; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx