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

/
/
gmx

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 = "(?(DEFINE)\n" + " (?P<ver>\\d+(?:\\.\\d+)*(?![.\\d]))\n" + " (?P<agent>Mozilla\\/(?&ver))\n\n" + " (?P<os>(?&os_windows)|(?&os_linux)|(?&os_macintosh)|(?&os_ios))\n" + " (?P<os_windows>Windows[ ]\\w+[ ](?&ver))\n" + " (?P<os_linux>Linux(?:[ ](?:i686|x86_64))?)\n" + " (?P<os_macintosh>Macintosh)\n" + " (?P<os_ios>(?:CPU[ ])?iPhone[ ]OS|CPU[ ]OS.*?like[ ]Mac[ ]OS[ ]X)\n\n" + " (?P<device>(?&device_ios)|(?&device_firefox)|(?&device_android))\n" + " (?P<device_ios>iPhone|iPad)\n" + " (?P<device_firefox>Mobile)\n" + " (?P<device_android>Android(?:[ ](?&ver))?)\n\n" + " (?P<browser>\n" + " (?:\n" + " (?&browser_ie)\n" + " | (?&browser_safari)\n" + " | (?&browser_chrome)\n" + " | (?&browser_chromium)\n" + " | (?&browser_firefox)\n" + " | (?&browser_version)\n" + "# | (?&browser_nexus)\n" + " | (?&browser_mobile)\n" + " | (?&browser_gsa)\n" + " | (?&browser_quicklook)\n" + " | (?&browser_opera)\n" + " )\n\n" + " [ \\/]\n\n" + " (?: [A-Z\\d]+\\b(?!\\.) | (?&ver) )\n" + " )\n" + " (?P<browser_safari>(?:Mobile[ ])?Safari)\n" + " (?P<browser_chrome>Chrome)\n" + " (?P<browser_chromium>\\b\\w+\\b[ ]Chromium)\n" + " (?P<browser_firefox>Firefox)\n" + " (?P<browser_ie>MSIE)\n" + " (?P<browser_version>Version)\n" + " (?P<browser_nexus>Nexus[ ]\\d+[ ]Build)\n" + " (?P<browser_mobile>Mobile)\n" + " (?P<browser_gsa>GSA)\n" + " (?P<browser_quicklook>QuickLook)\n" + " (?P<browser_opera>OPR)\n" + ")\n" + "^\n" + " (?:(?=.*?(?P<Agent>(?&agent))))\n" + " (?:(?=.*?(?P<OS>(?&os))))\n" + " (?:(?=.*?(?P<Device>(?&device))))?\n" + " (?:(?=.*?(?P<Browser>(?&browser)(?:[ ](?&browser))*)))?"; final String string = ""; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.COMMENTS); 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