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

const regex = /^https?:\/\/(?:www\.)?twitter\.com\/(?:#!\/)?@?([^/?#]*)(?:[?#].*)?$/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^https?:\\\/\\\/(?:www\\.)?twitter\\.com\\\/(?:#!\\\/)?@?([^\/?#]*)(?:[?#].*)?$', 'gm') const str = `https://twitter.com/TeleFootball https://twitter.com/GoalUSA https://twitter.com/goal_intl https://twitter.com/GoalItalia https://twitter.com/TMuk_news https://twitter.com/TMit_news https://twitter.com/footballitalia https://twitter.com/footballespana_ https://twitter.com/cmdotcom https://twitter.com/24CalcioMercato https://twitter.com/TuttoMercatoWeb https://twitter.com/GFN_France https://twitter.com/TopMercato https://twitter.com/sambafoot https://twitter.com/WhoScored https://twitter.com/fantagazzetta?original_referer=http%3A%2F%2Fwww.fantagazzetta.com%2F&profile_id=81810036&tw_i=618947696691384321&tw_p=embeddedtimeline&tw_w=329873702915276800 https://twitter.com/@UEFAcom https://twitter.com/lestransferts https://twitter.com/francefootball https://twitter.com/footmercato https://twitter.com/@FutbolFinanzas https://twitter.com/MARCAinENGLISH https://twitter.com/AS_Futbol https://twitter.com/mundodeportivo https://twitter.com/donbalon_com https://twitter.com/insidewldftball https://twitter.com/calciomercatoit https://twitter.com/_football411 https://twitter.com/BBCFtbl https://twitter.com/CNNFC https://twitter.com/foxsoccer https://twitter.com/ProSoccerTalk https://twitter.com/beINSportsUSA https://twitter.com/mirrorfootball https://twitter.com/ESPNFC https://twitter.com/DiMarzio https://twitter.com/tribalfootball https://twitter.com/WorldSoccerMag https://twitter.com/SkyFootball https://twitter.com/TheSunFootball https://twitter.com/foot365 https://twitter.com/Mercato365 https://twitter.com/sofoot https://twitter.com/abolapt https://twitter.com/fanatikcomtr https://twitter.com/kicker_bl_li https://twitter.com/vi_nl https://twitter.com/elfvoetbal https://twitter.com/tipsbladet https://twitter.com/KickOffMagazine https://twitter.com/sportalkorea https://twitter.com/Bundesliga_EN https://twitter.com/FFScout https://twitter.com/GAMBA_OFFICIAL https://twitter.com/Squawka https://twitter.com/StatsBomb https://twitter.com/mediotiempo https://twitter.com/soccerly`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions