Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

/
/
gi

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r#"(?i)(href|src|source|retinaSource|data)=(["|'][^"']*assets[^"']*\.\w{1,5})(\?[^"']*)?["|']"#).unwrap(); let string = "<a href=\"javascript://\" class=\"btn btn-continue-operation disabled\"> <span>Continuar</span> </a> <a href='javascript://\" class=\"btn btn-continue-operation disabled'> <span>Continuar</span> </a> <ul class=\"footer-legal l-adjacent-list\"> <li><a href=\"#external-content//genoma_transactional/cms_files/corporativo/seguridad-internet/index_transaccional.html\" class=\"footer-legal-element clr-gray.html\">{security}</a></li> <li><a href='#external-content//genoma_transactional/cms_files/corporativo/sobre-ing/condiciones-servicio-tarifa_transaccional.html' class=\"footer-legal-element clr-gray\">{link-legal-info-footer}</a></li> </ul> <link type=\"text/css\" href=\" assets/custom-css /infobolsa .css\" rel=\"stylesheet\" media=\"all\" charset=\"utf-8\"> <div class=\"fingerprint-views-storage-content-img txt-c\"> {>pp-image imageId=\"fingerprint-activation\" altText=\"fingerprint-activation\" source=\"assets/images/fingerprint-activation.png\" retinaSource=\"assets/images/retina/fingerprint-activation@2x.png\"/} </div> <img src=\"modules/cc-menu/assets/images/logo_cc.svg\" alt=\"Components catalog\"> <img src=\"assets/images/twyp_cash_circle.svg?query=34\"> <img src=\"assets/ircle.svg?hgt=76\"> {>pp-image imageId=\"budgets-tutorial-client-step3\" altText=\"budget-tutorial-step3\" source=\"components/budgets-tutorial/ASSETS/images/budgets-tutorial-client-step3.png\" {>pp-image imageId=\"budgets-tutorial-client-step3\" altText=\"budget-tutorial-step3\" source=\"components/budgets-tutorial/ASSETS/images/budgets-tutorial-client-step3.png\" {>pp-image source=\"assets/images/svg/logoING.svg\"/} <div data-selector=\"logo-ing\" class=\"padding-top-sm padding-left-sm pull-left\"> <img id=\"logo\" src=\"assets/images/svg/logoING.svg\" class=\"img-svg svg-header-logo login-header\"> </div> <audio data-selector=\"customer-connected-audio\"> <source src=\"modules/remote-advisor-agent/assets/audio/incomingCall.mp3\" type=\"audio/mp3\"/> </audio> <div class=\"col9\"> <div class=\"declaration-image-div\">{>pp-svg-image:no-products-other-bank imageId=\"declaration-image\" source=\"./assets/images/life-insurance-contract/cuestionario_riesgos.svg\"/}</div> <p class=\"h5 clr-dark-gray lic-declaration-remark\">{lic-risk-declaration-remark|s}</p> </div> <div data-region-id=\"login-dnie-image\" class=\"login-dnie-image\"><img src=\"assets/images/dni-logo.png\"/></div>"; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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 Rust, please visit: https://docs.rs/regex/latest/regex/