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

/
/
g

Test String

Code Generator

Generated Code

const regex = /(?m)^(?=(?:(?:(?(1)(?!))(.)|(?(2)(?!))(?!\1)(.)|(?(3)(?!))(?!\1|\2)(.)|(?(4)(?!))(?!\1|\2|\3)(.)|(?(5)(?!))(?!\1|\2|\3|\4)(.)|(?(6)(?!))(?!\1|\2|\3|\4|\5)(.)|(?(7)(?!))(?!\1|\2|\3|\4|\5|\6)(.)|(?(8)(?!))(?!\1|\2|\3|\4|\5|\6|\7)(.)|(?(9)(?!))(?!\1|\2|\3|\4|\5|\6|\7|\8)(.))\S*?){1,9}$)(?=(?:\1|\2|\3|\4|\5|\6|\7|\8|\9)*$)(?(DEFINE)(?<one>(?:(?!\1).)*\1)(?<two>(?:(?!\2).)*\2)(?<three>(?:(?!\3).)*\3)(?<four>(?:(?!\4).)*\4)(?<five>(?:(?!\5).)*\5)(?<six>(?:(?!\6).)*\6)(?<seven>(?:(?!\7).)*\7)(?<eight>(?:(?!\8).)*\8)(?<nine>(?:(?!\9).)*\9))(?:(?(1)(?=(?&one){1}(?!.*\1))(?(2)(?=(?&two){1}(?!.*\2))(?(3)(?=(?&three){1}(?!.*\3))(?(4)(?=(?&four){1}(?!.*\4))(?(5)(?=(?&five){1}(?!.*\5))(?(6)(?=(?&six){1}(?!.*\6))(?(7)(?=(?&seven){1}(?!.*\7))(?(8)(?=(?&eight){1}(?!.*\8))(?(9)(?=(?&nine){1}(?!.*\9)))))))))))|(?(1)(?=(?&one){2}(?!.*\1))(?(2)(?=(?&two){2}(?!.*\2))(?(3)(?=(?&three){2}(?!.*\3))(?(4)(?=(?&four){2}(?!.*\4))(?(5)(?=(?&five){2}(?!.*\5))(?(6)(?=(?&six){2}(?!.*\6))(?(7)(?=(?&seven){2}(?!.*\7))(?(8)(?=(?&eight){2}(?!.*\8))(?(9)(?=(?&nine){2}(?!.*\9)))))))))))|(?(1)(?=(?&one){3}(?!.*\1))(?(2)(?=(?&two){3}(?!.*\2))(?(3)(?=(?&three){3}(?!.*\3))(?(4)(?=(?&four){3}(?!.*\4))(?(5)(?=(?&five){3}(?!.*\5))(?(6)(?=(?&six){3}(?!.*\6))(?(7)(?=(?&seven){3}(?!.*\7))(?(8)(?=(?&eight){3}(?!.*\8))(?(9)(?=(?&nine){3}(?!.*\9)))))))))))|(?(1)(?=(?&one){4}(?!.*\1))(?(2)(?=(?&two){4}(?!.*\2))(?(3)(?=(?&three){4}(?!.*\3))(?(4)(?=(?&four){4}(?!.*\4))(?(5)(?=(?&five){4}(?!.*\5))(?(6)(?=(?&six){4}(?!.*\6))(?(7)(?=(?&seven){4}(?!.*\7))(?(8)(?=(?&eight){4}(?!.*\8))(?(9)(?=(?&nine){4}(?!.*\9)))))))))))|(?(1)(?=(?&one){5}(?!.*\1))(?(2)(?=(?&two){5}(?!.*\2))(?(3)(?=(?&three){5}(?!.*\3))(?(4)(?=(?&four){5}(?!.*\4))(?(5)(?=(?&five){5}(?!.*\5))(?(6)(?=(?&six){5}(?!.*\6))(?(7)(?=(?&seven){5}(?!.*\7))(?(8)(?=(?&eight){5}(?!.*\8))(?(9)(?=(?&nine){5}(?!.*\9)))))))))))|(?(1)(?=(?&one){6}(?!.*\1))(?(2)(?=(?&two){6}(?!.*\2))(?(3)(?=(?&three){6}(?!.*\3))(?(4)(?=(?&four){6}(?!.*\4))(?(5)(?=(?&five){6}(?!.*\5))(?(6)(?=(?&six){6}(?!.*\6))(?(7)(?=(?&seven){6}(?!.*\7))(?(8)(?=(?&eight){6}(?!.*\8))(?(9)(?=(?&nine){6}(?!.*\9)))))))))))|(?(1)(?=(?&one){7}(?!.*\1))(?(2)(?=(?&two){7}(?!.*\2))(?(3)(?=(?&three){7}(?!.*\3))(?(4)(?=(?&four){7}(?!.*\4))(?(5)(?=(?&five){7}(?!.*\5))(?(6)(?=(?&six){7}(?!.*\6))(?(7)(?=(?&seven){7}(?!.*\7))(?(8)(?=(?&eight){7}(?!.*\8))(?(9)(?=(?&nine){7}(?!.*\9)))))))))))|(?(1)(?=(?&one){8}(?!.*\1))(?(2)(?=(?&two){8}(?!.*\2))(?(3)(?=(?&three){8}(?!.*\3))(?(4)(?=(?&four){8}(?!.*\4))(?(5)(?=(?&five){8}(?!.*\5))(?(6)(?=(?&six){8}(?!.*\6))(?(7)(?=(?&seven){8}(?!.*\7))(?(8)(?=(?&eight){8}(?!.*\8))(?(9)(?=(?&nine){8}(?!.*\9)))))))))))|(?(1)(?=(?&one){9}(?!.*\1))(?(2)(?=(?&two){9}(?!.*\2))(?(3)(?=(?&three){9}(?!.*\3))(?(4)(?=(?&four){9}(?!.*\4))(?(5)(?=(?&five){9}(?!.*\5))(?(6)(?=(?&six){9}(?!.*\6))(?(7)(?=(?&seven){9}(?!.*\7))(?(8)(?=(?&eight){9}(?!.*\8))(?(9)(?=(?&nine){9}(?!.*\9)))))))))))).*/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?m)^(?=(?:(?:(?(1)(?!))(.)|(?(2)(?!))(?!\\1)(.)|(?(3)(?!))(?!\\1|\\2)(.)|(?(4)(?!))(?!\\1|\\2|\\3)(.)|(?(5)(?!))(?!\\1|\\2|\\3|\\4)(.)|(?(6)(?!))(?!\\1|\\2|\\3|\\4|\\5)(.)|(?(7)(?!))(?!\\1|\\2|\\3|\\4|\\5|\\6)(.)|(?(8)(?!))(?!\\1|\\2|\\3|\\4|\\5|\\6|\\7)(.)|(?(9)(?!))(?!\\1|\\2|\\3|\\4|\\5|\\6|\\7|\\8)(.))\\S*?){1,9}$)(?=(?:\\1|\\2|\\3|\\4|\\5|\\6|\\7|\\8|\\9)*$)(?(DEFINE)(?<one>(?:(?!\\1).)*\\1)(?<two>(?:(?!\\2).)*\\2)(?<three>(?:(?!\\3).)*\\3)(?<four>(?:(?!\\4).)*\\4)(?<five>(?:(?!\\5).)*\\5)(?<six>(?:(?!\\6).)*\\6)(?<seven>(?:(?!\\7).)*\\7)(?<eight>(?:(?!\\8).)*\\8)(?<nine>(?:(?!\\9).)*\\9))(?:(?(1)(?=(?&one){1}(?!.*\\1))(?(2)(?=(?&two){1}(?!.*\\2))(?(3)(?=(?&three){1}(?!.*\\3))(?(4)(?=(?&four){1}(?!.*\\4))(?(5)(?=(?&five){1}(?!.*\\5))(?(6)(?=(?&six){1}(?!.*\\6))(?(7)(?=(?&seven){1}(?!.*\\7))(?(8)(?=(?&eight){1}(?!.*\\8))(?(9)(?=(?&nine){1}(?!.*\\9)))))))))))|(?(1)(?=(?&one){2}(?!.*\\1))(?(2)(?=(?&two){2}(?!.*\\2))(?(3)(?=(?&three){2}(?!.*\\3))(?(4)(?=(?&four){2}(?!.*\\4))(?(5)(?=(?&five){2}(?!.*\\5))(?(6)(?=(?&six){2}(?!.*\\6))(?(7)(?=(?&seven){2}(?!.*\\7))(?(8)(?=(?&eight){2}(?!.*\\8))(?(9)(?=(?&nine){2}(?!.*\\9)))))))))))|(?(1)(?=(?&one){3}(?!.*\\1))(?(2)(?=(?&two){3}(?!.*\\2))(?(3)(?=(?&three){3}(?!.*\\3))(?(4)(?=(?&four){3}(?!.*\\4))(?(5)(?=(?&five){3}(?!.*\\5))(?(6)(?=(?&six){3}(?!.*\\6))(?(7)(?=(?&seven){3}(?!.*\\7))(?(8)(?=(?&eight){3}(?!.*\\8))(?(9)(?=(?&nine){3}(?!.*\\9)))))))))))|(?(1)(?=(?&one){4}(?!.*\\1))(?(2)(?=(?&two){4}(?!.*\\2))(?(3)(?=(?&three){4}(?!.*\\3))(?(4)(?=(?&four){4}(?!.*\\4))(?(5)(?=(?&five){4}(?!.*\\5))(?(6)(?=(?&six){4}(?!.*\\6))(?(7)(?=(?&seven){4}(?!.*\\7))(?(8)(?=(?&eight){4}(?!.*\\8))(?(9)(?=(?&nine){4}(?!.*\\9)))))))))))|(?(1)(?=(?&one){5}(?!.*\\1))(?(2)(?=(?&two){5}(?!.*\\2))(?(3)(?=(?&three){5}(?!.*\\3))(?(4)(?=(?&four){5}(?!.*\\4))(?(5)(?=(?&five){5}(?!.*\\5))(?(6)(?=(?&six){5}(?!.*\\6))(?(7)(?=(?&seven){5}(?!.*\\7))(?(8)(?=(?&eight){5}(?!.*\\8))(?(9)(?=(?&nine){5}(?!.*\\9)))))))))))|(?(1)(?=(?&one){6}(?!.*\\1))(?(2)(?=(?&two){6}(?!.*\\2))(?(3)(?=(?&three){6}(?!.*\\3))(?(4)(?=(?&four){6}(?!.*\\4))(?(5)(?=(?&five){6}(?!.*\\5))(?(6)(?=(?&six){6}(?!.*\\6))(?(7)(?=(?&seven){6}(?!.*\\7))(?(8)(?=(?&eight){6}(?!.*\\8))(?(9)(?=(?&nine){6}(?!.*\\9)))))))))))|(?(1)(?=(?&one){7}(?!.*\\1))(?(2)(?=(?&two){7}(?!.*\\2))(?(3)(?=(?&three){7}(?!.*\\3))(?(4)(?=(?&four){7}(?!.*\\4))(?(5)(?=(?&five){7}(?!.*\\5))(?(6)(?=(?&six){7}(?!.*\\6))(?(7)(?=(?&seven){7}(?!.*\\7))(?(8)(?=(?&eight){7}(?!.*\\8))(?(9)(?=(?&nine){7}(?!.*\\9)))))))))))|(?(1)(?=(?&one){8}(?!.*\\1))(?(2)(?=(?&two){8}(?!.*\\2))(?(3)(?=(?&three){8}(?!.*\\3))(?(4)(?=(?&four){8}(?!.*\\4))(?(5)(?=(?&five){8}(?!.*\\5))(?(6)(?=(?&six){8}(?!.*\\6))(?(7)(?=(?&seven){8}(?!.*\\7))(?(8)(?=(?&eight){8}(?!.*\\8))(?(9)(?=(?&nine){8}(?!.*\\9)))))))))))|(?(1)(?=(?&one){9}(?!.*\\1))(?(2)(?=(?&two){9}(?!.*\\2))(?(3)(?=(?&three){9}(?!.*\\3))(?(4)(?=(?&four){9}(?!.*\\4))(?(5)(?=(?&five){9}(?!.*\\5))(?(6)(?=(?&six){9}(?!.*\\6))(?(7)(?=(?&seven){9}(?!.*\\7))(?(8)(?=(?&eight){9}(?!.*\\8))(?(9)(?=(?&nine){9}(?!.*\\9)))))))))))).*', 'g') const str = `------------------------------ match_words = ------------------------------ arraigning nonordered abadbacdcacbdbdc mesosome ananna unendued tromometer caucasus intestines i deed horseshoer happenchance reappear deeded pullup arraigning testes mononymy scintillescent couscous ------------------------------ not_match_words = ------------------------------ edified unreverberating underpass interinsert pilfered nippiness gregarinian deicide nonaristocratic rototiller ozonizing museums backbreaker interradiated antistalling naturalize equitriangular reparticipate ppd miasmas cabbage `; // 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