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 = /news_/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('news_', 'gm') const str = `news_arts news_offbeat news_buss news_features news_latest news_sport news_topstories news_politics news_health news_scitech news_aust news_world news_rural news_indigenous news_enviro news_morning_optin news_alerts_optin news_afternoon_optin abc-splash-secondary_optin abc-4kids_optin 4-corners_optin mp_optin_interests abc-science-updates_optin abc-open_optin 702-abc-sydney_optin btn_optin abc-radio-national-late-night-live_optin abc-rural_optin abc-religion_optin 891-abc-adelaide_optin abc-national-rural-news_optin abc-tv-countdown-to-3_optin dig_optin abc-gardening_optin abc-splash-stem_optin abc-radio-national_optin abcdailynewsemail_optin abc-radio-national-music_optin abc-tv-qanda_optin abc-arts-culture_optin abc-shop-news_optin 720-abc-perth_optin abc-splash-primary_optin abc-tv-switchedon_optin 666-abc-canberra_optin abc-tv-iview_optin abc-heywire_optin triplej-unearthed_optin 774-abc-melbourne-books_optin australia-plus-sports-lounge_optin mp_optin_local abc-radio-national-law-report_optin abc-radio-national-saturday-extra_optin australia-plus-china_optin abc-radio-national-creative-audio-unit_optin abc-jazz_optin 936-abc-hobart-wireless-news_optin j-mail_optin mp_optin_highlights 1057-abc-darwin_optin 612-abc-brisbane_optin australia-plus_optin 774-abc-melbourne_optin abctours_optin abc-classic-fm_optin abc-tv-compass_optin abc-health-updates_optin interest_children interest_history interest_sport interest_music_alternative interest_indigenous interest_comedy interest_music_easy interest_attribute_downloads interest_politics interest_environment interest_attribute_radio interest_law interest_documentary interest_community interest_music_country interest_regional interest_music_nostalgia interest_music_jazz interest_ghealth interest_media interest_books interest_education interest_games interest_attribute_websites interest_drama interest_attribute_tv interest_naturalhistory interest_attribute_previews interest_general_news interest_cooking interest_music_rock interest_music_blues interest_lifestyle interest_entertainment interest_travel interest_music_classical interest_youth interest_attribute_shops interest_business interest_religion interest_gardening interest_science interest_arts`; // 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