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

/
/
mg

Test String

Code Generator

Language

Generated Code

const regex = /(?:\\')?[^']*(?<!\\)'((?:\\[^']|[^ֿֿֿֿֿֿֿֿ\\']|\\')*)'|'((?:[^'\\]*\\'[^'\\]*)+)'/mg; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?:\\\\\')?[^\']*(?<!\\\\)\'((?:\\\\[^\']|[^ֿֿֿֿֿֿֿֿ\\\\\']|\\\\\')*)\'|\'((?:[^\'\\\\]*\\\\\'[^\'\\\\]*)+)\'', 'mg') const str = `'test' more'test' 'test'more \\'no'yes' a 'one' and 'two' and 'three'... nothing at all '' ''test test'' te''st 'This is not wrong' and 'this isn\\'t either' 'tw\\'o repl\\'acements' in 't\\'wo stri\\'ngs'. '\\\\'' ''' 'test1'\\n'test2' '''' GVNBR!a4GO'Ic1>7E<9?l)gaj0%4*{dX2+6s&__F8-IZk.^|A528/!fc_b#<uO0C[Vod;ws0eqL\$#(J28>d^l#421[6EwbnZH/zTP>\\",&e&Qx^K!yd2!dX;z.,r)Qb2=f0Xz**R |DB?NOUAG6yvGU1bX\`m5hE@/\\"uIm=hp{K]17L-L5v=eI#!{Q^O5To1!0sJ!{kl~_yV&N&=oTr\$?Ou[niG"'D0"/ZJZUey3{O04JkM8j/S7\\"wqs&LhHBxxnX/l}*1-rF)ou/JeWx-*C!Sp1db|1Tcd6xYf f {;nF, yy]fKAf<6H]T74R}1k#HUIc|]Rqz-Ce72-D%vz&Nm rw=81:1_Y&e,34pL.amQmAoj*m;6ObGN]#u71j%+H\\'}4}b~|nTy]<B7umVMx;tN%QUPY=P\`67F4Rert4Cy'PMOJwnmc2s\\'4f<EEmh,yj3Uf/u[lbc/dAgl*Xd%oY,T;+\\"2_f{BzP\`.#v(yGtX\\'O+4eU[P.3&1s+ xm! `; // 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