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
Processing...

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 = "(?<scheme>[^!$&'()*,;=@//:\\s]+):(?<authority>//(?<userinfo>(?<username>[\\w\\.\\-!$&'()*,;=]+):?(?<password>[\\w\\.\\-!$&'()*,;=]+)?@)?(?<host>[^\\s\\n\\t\\r/:\\[\\]]+|\\[[^\\s\\n\\t\\r/:\\[\\]]+\\]):?(?<port>\\d{1,5})?)?[/]?(?<path>[^\\s\\?#]{1,}(?:\\?(?<query>[^\\s#]+))?(?:#(?<fragment>[^\\s]+))?)?"; final String string = "example from wikipedia URI:\n" + " userinfo host port\n" + " ┌─┴─────┐\n" + " user pass\n" + " ┌──┴───────┴───┐┌──────┴──────┐ ┌┴─┐\n" + " https://john.doe:example@www.example.com:1234/forum/questions/?tag=networking&order=newest#top\n" + " └─┬─┘ └─────────────┬─────────────┘└───────┬───────┘ └────────────┬────────────┘ └┬┘\n" + " scheme authority path query fragment\n" + " userinfo host port\n" + " ┌──┴───┐ ┌──────┴──────┐ ┌┴─┐\n" + " https://john.doe@www.example.com:1234/forum/questions/?tag=networking&order=newest#:~:text=whatever\n" + " └─┬─┘ └─────────────┬─────────────┘└───────┬───────┘ └────────────┬────────────┘ └───────┬───────┘\n" + " scheme authority path query fragment\n\n" + " ldap://[2001:db8::7]/c=GB?objectClass?one\n" + " └┬─┘ └─────┬─────┘└─┬─┘ └──────┬──────┘\n" + " scheme authority path query\n\n" + " mailto:John.Doe@example.com\n" + " └─┬──┘ └────┬─────────────┘\n" + " scheme path\n\n" + " news:comp.infosystems.www.servers.unix\n" + " └┬─┘ └─────────────┬─────────────────┘\n" + " scheme path\n\n" + " tel:+1-816-555-1212\n" + " └┬┘ └──────┬──────┘\n" + " scheme path\n\n" + " telnet://192.0.2.16:80/\n" + " └─┬──┘ └─────┬─────┘│\n" + " scheme authority path\n\n" + " urn:oasis:names:specification:docbook:dtd:xml:4.1.2\n" + " └┬┘ └──────────────────────┬──────────────────────┘\n" + " scheme path"; final Pattern pattern = Pattern.compile(regex); 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