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

/
/
gim

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 = "^(?:.*)testhack(?:[[:alnum:][:blank:]\\\\\\/\\._-]*)(?<!\\.git|\\.gitignore)$"; final String string = "/home/kwaadpepper/testhack\n" + "/home/kwaadpepper/testhack/TwitterReport\n" + "/home/kwaadpepper/testhack/test\n" + "/home/kwaadpepper/testhack/TwitterReport/.git\n" + "/home/kwaadpepper/testhack/TwitterReport/.gitignore\n" + "/home/kwaadpepper/testhack/TwitterReport/LICENSE\n" + "/home/kwaadpepper/testhack/TwitterReport/README.md\n" + "/home/kwaadpepper/testhack/TwitterReport/log_Error.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/log_reported_2015111731047.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/log_reported_2015111761057.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/log_reported_2015111762323.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/log_reported_201511176245.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/log_suspended.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/twitterReport.py\n" + "/home/kwaadpepper/testhack/TwitterReport/twitter_accounts.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/twitter_accounts2.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/twitter_accounts2.txt.save\n" + "/home/kwaadpepper/testhack/TwitterReport/twitter_accounts3.txt\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/HEAD\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/branches\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/config\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/hooks/pre-applypatch.sample\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/hooks/pre-commit.sample\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/hooks/pre-push.sample\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/hooks/pre-rebase.sample\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/hooks/prepare-commit-msg.sample\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/hooks/update.sample\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/info/exclude\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/objects/21\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/objects/4d\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/objects/59\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/objects/69\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/objects/70\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/objects/f9/00faba8624d5cbfee6032ad6266c6722b19457\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/refs/heads\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/refs/remotes\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/refs/tags\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/refs/heads/master\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/refs/remotes/origin\n" + "/home/kwaadpepper/testhack/TwitterReport/.git/refs/remotes/origin/HEAD"; final Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE | 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