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

Substitution
Processing...

Code Generator

Language

Generated Code

re = /(?:(?!<li>).)*<li>.*?<a href="([^"]+)".*?alt="On Contact: ([^"]+)".*?<p[^>]*>((?:(?!<\/p>).)+?)<\/p>.*?<p[^>]*>([^<]+)<(?:(?!<li>).)*/m str = ' <li><p style="margin-bottom: 0in"><a href="https://www.rt.com/shows/on-contact/550756-america-long-war-race/">On Contact: Race and America\'s long war </a> </p> <p style="margin-bottom: 0in"><a href="https://www.rt.com/shows/on-contact/550756-america-long-war-race/"> <font color="#000080"> <img src="rt.com-on_contact-220405-no_blurb_html_1dff87941f1c724a.jpg" name="Image1" alt="On Contact: Race and America\'s long war" align="bottom" width="280" height="157" border="1"/> </font> </a> </p> <p style="margin-bottom: 0in">On the show, Chris Hedges discusses America\'s inner and outer wars and its nexus with capitalism and empire with Professor of Social and Cultural Analysis and History at New York University Nikhil Pal Singh. The internal violence in the United... </p> <p style="margin-bottom: 0in">Feb 27, 2022 10:36</p> <li><p style="margin-bottom: 0in"><a href="https://www.rt.com/shows/on-contact/550319-george-washington-genocidal-colonist/"> <font color="#000080"> <img src="rt.com-on_contact-220405-no_blurb_html_198feb67032166ff.png" name="Image3" alt="On Contact: George Washington and the legacy of white supremacy" align="bottom" width="280" height="157" border="1"/> </font> </a> </p> <p style="margin-bottom: 0in"><strong><a href="https://www.rt.com/shows/on-contact/550319-george-washington-genocidal-colonist/">On Contact: George Washington and the legacy of white supremacy </a></strong> </p> <p style="margin-bottom: 0in">On the show, Chris Hedges discusses George Washington, the fallible human being and one of the principal architects of the United States, with author Nathaniel Philbrick. As America fractures into ideologically hostile camps, it colors how we... </p> <p style="margin-bottom: 0in">Feb 25, 2022 09:09 </p> <li>[...]' subst = '$4\\t$2\\t$1\\t$3\\n' result = str.gsub(re, subst) # Print the result of the substitution puts result

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html