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 = "(([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)(\\s*;\\s*|\\s*$))*"; final String string = "a@a.c\n" + "a@a.co\n" + "sbreedebd@home.pl\n" + "sgerrensbe@free.fr\n" + "eishakbf@skyrock.com\n" + "dstansallbg@japanpost.jp\n" + "mbrittanbh@amazon.co.uk\n" + "slauridsenbi@home.pl\n" + "dgrabbambj@imageshack.us\n" + "etossellbk@apple.com\n" + "smoodycliffebl@sogou.com\n" + "rtoothillbm@wisc.edu\n" + "asebbornbn@infoseek.co.jp\n" + "dgherardescibo@jalbum.net\n" + "aarnaldybp@europa.eu\n" + "aballantinebq@bigcartel.com\n" + "cgiraudatbr@phpbb.com\n" + "hmaccoughenbs@answers.com\n" + "emattessenbt@dot.gov\n" + "saronowbu@exblog.jp\n" + "ckorneichukbv@berkeley.edu\n" + "nroderigobw@yale.edu\n" + "ealeksandrevbx@netvibes.com\n" + "ebolterby@eepurl.com\n" + "cgaitherbz@theatlantic.com\n" + "sfeedomec0@shutterfly.com\n" + "ahatfullc1@ocn.ne.jp\n" + "mbythwayc2@whitehouse.gov\n" + "mleitherc3@dyndns.org\n" + "gtouretc4@icq.com\n" + "lmcnaec5@cam.ac.uk\n" + "tculveyc6@si.edu\n" + "fportwainc7@themeforest.net\n" + "eshivellc8@xing.com\n" + "mrheltonc9@howstuffworks.com\n" + "rrenodenca@walmart.com\n" + "ibaudcb@apple.com\n" + "amckerncc@domainmarket.com\n" + "aszymczykcd@vk.com\n" + "edittyce@patch.com\n" + "eibertcf@cyberchimps.com\n" + "apagencg@google.cn\n" + "bcousinsch@elpais.com\n" + "edockrellci@kickstarter.com\n" + "peasterlingcj@vkontakte.ru\n" + "mmoenck@mail.ru\n" + "nstitwellcl@admin.ch\n" + "mreginacm@techcrunch.com\n" + "fbindoncn@nps.gov\n" + "vpocklingtonco@seattletimes.com\n" + "lbarabichcp@privacy.gov.au\n" + "fmcbeathcq@thetimes.co.uk\n" + "jbohillscr@bandcamp.com\n" + "aworkescs@amazon.de\n" + "mmarusyakct@zdnet.com\n" + "lmcaleescu@simplemachines.org\n" + "bdemetzcv@illinois.edu\n" + "jdominiquecw@economist.com\n" + "easlottcx@ftc.gov\n" + "adewhirstcy@marriott.com\n" + "mstaddomcz@slideshare.net\n" + "aealamd0@ibm.com\n" + "dweblind1@youtube.com\n" + "palasdaird2@unesco.org\n" + "rfrearsond3@disqus.com\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