Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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

/
/
gm

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"^(?!\[HMR\]).*$"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" [WDS] App hot update... [HMR] Checking for updates on the server... [HMR] Updated modules: [HMR] - ./src/$$_lazy_route_resource lazy recursive [HMR] - ./node_modules/@angular/core/fesm5/core.js [HMR] - ./src/hmr.ts [HMR] - ./src/app/app.module.ts [HMR] - ./src/app/shared/guards/auth.guard.ts [HMR] - ./node_modules/@angular/router/fesm5/router.js [HMR] - ./node_modules/@angular/common/fesm5/common.js [HMR] - ./node_modules/@angular/platform-browser/fesm5/platform-browser.js [HMR] - ./src/app/shared/services/jwt.service.ts [HMR] - ./node_modules/@angular/common/fesm5/http.js [HMR] - ./src/app/shared/guards/role.guard.ts [HMR] - ./node_modules/@ngx-progressbar/core/fesm5/ngx-progressbar-core.js [HMR] - ./node_modules/@auth0/angular-jwt/index.js [HMR] - ./node_modules/@auth0/angular-jwt/src/jwt.interceptor.js [HMR] - ./node_modules/@auth0/angular-jwt/src/jwthelper.service.js [HMR] - ./node_modules/@auth0/angular-jwt/src/jwtoptions.token.js [HMR] - ./src/app/shared/modules/layout/layout.module.ts [HMR] - ./src/app/shared/modules/clock/clock.module.ts [HMR] - ./src/app/shared/modules/clock/clock.component.ts [HMR] - ./src/app/shared/modules/layout/layout.routing.ts [HMR] - ./src/app/shared/modules/layout/account/account.page.ts [HMR] - ./src/app/shared/modules/layout/default/default.page.ts [HMR] - ./src/app/shared/modules/layout/default/sidebar-menu/sidebar-menu.component.ts [HMR] - ./src/app/shared/modules/layout/default/header/header.component.t sdfadsfas asdf asdfasd fasdf asdfasdf asd fa sd fasdfasf asdf asdfasdfas dfasd df """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let matches = regex.matches(in: testString, range: stringRange) var result: [[String]] = [] for match in matches { var groups: [String] = [] for rangeIndex in 1 ..< match.numberOfRanges { let nsRange = match.range(at: rangeIndex) guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue } let string = (testString as NSString).substring(with: nsRange) groups.append(string) } if !groups.isEmpty { result.append(groups) } } print(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 Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression