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

r"""
"""
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 = "\\bEmail:\\s*<a\\s[^<>]*\\bhref=\"mailto:([^\"]+)\""; final String string = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n" + "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n" + "<html>\n" + "<head></head>\n" + "<body>\n" + "<a name=\"top\"></a>Back to Category Index</a></p>\n" + "<p>-----------------------------------<br/></p>\n\n" + "67)<a name=\"e1h1\" id=\"e1h1\"></a> Summary: Solar Eclipse 2024 Travel\n" + "<br/><br/>\n" + "<p>Name: laure gem wilson\n" + "Roadtrippers\n" + "</p>Category: Travel\n" + "<br/><br/>\n" + "Email: <a href=\"mailto:query-e1h1@email.net\">query-e1h1@email.net</a>\n" + "<br/><br/>\n" + "Outlet: Roadtrip<br/><br/>\n" + "Deadline: 7:00 PM EST - 8 July\n" + "<br/><br/>\n" + "<p>\n" + "Query: \n" + "<br/><br/>\n" + "Hi, I am on assignment to write a feature about planning a road<br/>trip to experience the Solar Eclipse 2024, including path of<br/>totality, advice about viewing, and recommendations for when and<br/>where to book accommodations, thanks!<br/>\n" + "</p>\n" + "<p>\n" + "Requirements: \n" + "<br /><br />\n" + "Must be domestic USA<br/>\n" + "</p>\n" + "<p><a href=\"#top\">Back to Top</a> <a href=\"#Travel\">Back to Category Index</a></p>\n" + "<p>-----------------------------------<br/>\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