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 = "^(?(DEFINE)(?'word'(?:[a-zA-Z0-9!?'\"&\\.,+@%~$]|(?<! )-(?! ))+)(?'words'(?&word)(?: (?&word))*?)(?'nothe'(?<!, (?i:a))(?<!, (?i:the|les)))(?'ver_prefix'Rev|Proto|Alpha|Beta))(?'title'(?&words)(?&nothe))(?'subtitle' - (?&words))*?(?'upd' (?:Update|DLC - (?&words)))?(?'region' \\((?:(?:A|As|B|C|Ch|Nl|E|F|G|Gr|Hk|I|J|K|No|R|S|Sw|U|Uk|Tw|W))+\\))?(?'version' \\[(?:(?:(?&ver_prefix) )?(?:(?'_ver'[\\da-zA-Z]+)(?:\\.(?&_ver))+|\\d\\d\\d\\d-\\d\\d-\\d\\d(?:T\\d+)?)|(?&ver_prefix)( (?:[A-Z]|\\d+|early))?)\\])?(?'part' \\(Dis(?:c|k) \\d+\\))?(?'language' \\((?'_lang'(?:F-)?(?:Ja|En|Fr|De|Es|It|Nl|Ca|Fi|No|Sv|Da|Zh(?:-Hant|-Hans)?|Pt|Ru|Ko|Pl))(?:,?(?&_lang))*\\))?(?'randomshit'(?: \\[DEMO\\])?(?'lossy' \\[LOSSY\\])?(?: \\[Sample\\])?(?: \\(Promo\\))?(?: \\(Unl\\))?)(?'features' \\[(?'_feat'[a-zA-Z]+)(?:, ?(?&_feat))*\\])?(?'ext'\\.(?:gbc|gb|nsp|xci|(nkit\\.)?rvz|gcz|wbfs|wad|gba|type|cia|3ds|nds|nes|sfc|smc|n64|z64|wux|gg|md|sms|iso|pce|chd))$"; final String string = "Amazing Spider Man (UE).gb\n" + "Otto's Ottifanten - Baby Bruno's Nightmare (E) (En,Fr,De,Es).gb\n" + "Pokemon Kristall (G).gbc\n" + "A Hat in Time DLC - Nyakuza Metro [1.1.0].nsp\n" + "Pokemon Card GB2 - GR Dan Sanjou! (J).gbc\n" + "Asphalt 9 Legends [1.3.1].nsp\n" + "Animal Crossing New Horizons DLC - Special Order Ticket Pocket Camp tie-in campaign.nsp\n" + "Pokemon Pinball (E) (En,Fr,De,Es,It) [S,DMG].gbc\n" + "Arcade Hits - Moon Patrol & Spy Hunter (UE) [DMG].gbc\n" + "Daikatana (U) [Proto 2000-04-19] [DMG].gbc\n" + "Hang Time Basketball (E) (Unl).gbc\n" + "Pokemon Green (J) [1.0] (F-En).gb\n" + "LSDJ [9.2.L].gb\n" + "Keep Talking and Nobody Explodes Update [1.2.0].nsp\n" + "Sonic Mania Plus [1.0.4] (En,Ja,Fr,De,Es,It,Zh).xci\n" + "Spelunky [1.22.2a].nsp\n" + "Chrono Cross (U) (Disc 1).chd\n" + "Chrono Cross (U) (Disc 2).chd\n" + "Fear Effect 2 - Retro Helix (E) (Disc 1) (En,Fr,De).chd\n" + "Ren & Stimpy Show - Buckeroo$! (U).sfc\n" + "PGA European Tour Golf (E) [Beta B.29] (En,De).z64\n" + "007 - The World Is Not Enough (U) [Beta 21].z64\n" + "007 - The World Is Not Enough (U) [Beta 2.00].z64\n" + "Pokemon Yellow (UE) [C].gb\n" + "Shadowgate 64 - Trials of the Four Towers (U) [Beta] (En,Es).z64\n" + "Mario Kart Wii (U) (En,Fr,Es) [LOSSY].wbfs"; 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