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 = "^(?P<name>[\\w\\-\\.]+)-(?P<version>v?\\d+(\\.\\d+)?(\\.\\d+)?(-[\\w\\-]+(\\.[\\w\\-]+)*)?(\\+[\\w\\-]+(\\.[\\w\\-]+)*)?)(?P<ext>\\.[\\w\\-]+)$"; final String string = "ansi-escapes-4.3.1.tgz\n" + "babel-eslint-10.1.0.tgz\n" + "chance-1.1.7.tgz\n" + "cli-cursor-3.1.0.tgz\n" + "eslint-7.13.0.tgz\n" + "faker-5.1.0.tgz\n" + "forever-monitor-3.0.1.tgz\n" + "fs-extra-9.0.1.tgz\n" + "lorem-ipsum-2.0.3.tgz\n" + "micromatch-4.0.2.tgz\n" + "mongoose-5.10.13.tgz\n" + "puppeteer-5.4.1.tgz\n" + "puppeteer-extra-3.1.15.tgz\n" + "puppeteer-extra-plugin-stealth-2.6.3.tgz\n" + "random-email-1.0.3.tgz\n" + "random-useragent-0.5.0.tgz\n" + "random-words-1.1.1.tgz\n" + "slice-ansi-4.0.0.tgz\n" + "uuid-8.3.1.tgz\n" + "validator-13.1.17.tgz\n" + "wrap-ansi-7.0.0.tgz\n" + "font-awesome-5.11.2.tgz\n" + "react-dom-16.13.1.tgz\n" + "bootstrap-4.5.2.tgz\n" + "moment-duration-format-2.3.2.tgz\n" + "imagesloaded-4.1.tgz\n" + "flickity-2.0.tgz\n" + "lomster-1.tgz\n" + "unicorn-1.2.3-alpha.10.beta.0.tgz\n" + "rainbow-v1.1.1.tgz\n" + "object.assign-4.1.4.tgz\n" + "hello_world-0.0.3.tgz\n" + "typescript-package-1-1.0.2.tgz\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