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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?:\\\\')?[^']*(?<!\\\\)'((?:\\\\[^']|[^ֿֿֿֿֿֿֿֿ\\\\']|\\\\')*)'|'((?:[^'\\\\]*\\\\'[^'\\\\]*)+)'"; final String string = "'test' \n" + "more'test' \n" + "'test'more \n" + "\\'no'yes' \n" + "a 'one' and 'two' and 'three'... \n" + "nothing at all \n" + "'' \n" + "''test \n" + "test'' \n" + "te''st \n" + "'This is not wrong' and 'this isn\\'t either' \n" + "'tw\\'o repl\\'acements' in 't\\'wo stri\\'ngs'. \n" + "'\\\\'' \n" + "''' \n" + "'test1'\\n'test2' \n" + "'''' \n\n" + "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\n\n" + "{;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!\n"; 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