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

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?:(\\d{2})(?:0(?=(?:\\1)1)|1(?=(?:\\1)2)|2(?=(?:\\1)3)|3(?=(?:\\1)4)|4(?=(?:\\1)5)|5(?=(?:\\1)6)|6(?=(?:\\1)7)|7(?=(?:\\1)8)|8(?=(?:\\1)9))|(\\d)(?:09(?=(?:\\2)10)|19(?=(?:\\2)20)|29(?=(?:\\2)30)|39(?=(?:\\2)40)|49(?=(?:\\2)50)|59(?=(?:\\2)60)|69(?=(?:\\2)70)|79(?=(?:\\2)80)|89(?=(?:\\2)90))|099(?=100)|199(?=200)|299(?=300)|399(?=400)|499(?=500)|599(?=600)|699(?=700)|799(?=800)|899(?=900)){4,}\\d{3}"; final String string = "531131231331431587\n" + "zzz005006007008009010011012zzz\n" + "551651751851952052152287\n" + "571771871972087\n" + "582682882983083183283487\n" + "593393593693793893994094194387\n" + "564965065165265365487\n" + "575775875976076187\n" + "526826927027127227487\n" + "547747847948048187\n" + "518919019119219387\n" + "583183283383483583783984084184284387\n" + "zzz097098099100101102zzz\n" + "zzz198199200201202zzz\n" + "zzz297298299300301302zzz\n" + "zzz396397398399400401zzz\n" + "zzz497498499500501zzz\n" + "zzz598599600601602603zzz\n" + "zzz697698699700701zzz\n" + "zzz796797798799800801zzz\n" + "zzz898899900901902903zzz\n" + "zzz200201202203204zzz\n" + "zzz295296297298299zzz\n" + "zzz296297298299300zzz\n" + "500000100200300487\n" + "599599699799899987\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