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

/
/
xmg

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 = "\n" + "# allow multiple groups with the same name\n" + "(?J)\n" + "# protocol user host-ip port path path path querystring fragment\n" + "^\n" + "#protocol\n" + "(?:(?<scheme>[a-zA-Z][a-zA-Z\\d+-.]*):)?\n" + "(?|\n" + " #slash-slash\n" + " \\/\\/\n" + " #userinfo\n" + " (?:\n" + " #user\n" + " (?<user>[a-zA-Z\\d\\-._~\\!$&'()*+,;=%]*)\n" + " #password\n" + " (?::(?<pass>[a-zA-Z\\d\\-._~\\!$&'()*+,;=:%]*))?\n" + " @)?\n" + " #host-ip\n" + " (?<host>(?:[a-zA-Z\\d-.%]+)|(?:\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})|(?:\\[(?:[a-fA-F\\d.:]+)\\]))?\n" + " #port\n" + " (?::(?<port>\\d*))?\n" + " #slash-path\n" + " (?<path>\n" + " (?:\\/ [a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%]* )*\n" + " )\n\n" + " #slash-path\n" + " |(?<user>)(?<pass>)(?<host>)(?<port>)\n" + " (?<path>\\/ [a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%]+(?:\\/[a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%]*)*)?\n\n" + " #path\n" + " |(?<user>)(?<pass>)(?<host>)(?<port>)\n" + " (?<path> [a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%]+(?:\\/[a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%]*)*)\n\n" + ")?\n" + "#querystring\n" + "(?:\\?(?<query>[a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%\\/?]*))?\n" + "#fragment\n" + "(?:\\#(?<fragment>[a-zA-Z\\d\\-._~\\!$&'()*+,;=:@%\\/?]*))?\n" + "$\n"; final String string = "https://regex101.com/\n" + "https://regex101.com/thing/blah.foo\n" + "https://regex101.com:28801/thing/blah/patterns?where_foo=bar&where_primary_access_node=true\n" + "https://regex101.com:8443/thing/index.html#/landing"; final Pattern pattern = Pattern.compile(regex, Pattern.COMMENTS | 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