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

/
/
g

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#"(id="mce_[^"]+")"#).unwrap(); let string = "<section id=\"defaultSection\"> <div class=\"container\"> <div class=\"row\" id=\"mce_30\" ><div class=\"third centerText overflowHidden\"><div><img src=\"http://templates.weesoo.com/dummy1.jpg\" class=\"fullWidth\" data-mce-src=\"http://templates.weesoo.com/dummy1.jpg\"></div><h3>Lorem ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><div><a href=\"#\" class=\"btnColor1 floatRight\" data-mce-href=\"#\">En savoir +&nbsp;</a></div></div><div class=\"third centerText overflowHidden\"><div><img src=\"http://templates.weesoo.com/dummy1.jpg\" class=\"fullWidth\" data-mce-src=\"http://templates.weesoo.com/dummy1.jpg\"></div><h3>Lorem ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><div><a href=\"#\" class=\"btnColor1 floatRight\" data-mce-href=\"#\">En savoir +</a></div></div><div class=\"third centerText overflowHidden\"><div><img src=\"http://templates.weesoo.com/dummy1.jpg\" class=\"fullWidth\" data-mce-src=\"http://templates.weesoo.com/dummy1.jpg\" data-mce-selected=\"1\"></div><h3>Lorem ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><div><a href=\"#\" class=\"btnColor1 floatRight\" data-mce-href=\"#\">En savoir +</a></div></div><div id=\"mceResizeHandlenw\" data-mce-bogus=\"all\" class=\"mce-resizehandle\" unselectable=\"true\" style=\"cursor: nw-resize; margin: 0px; padding: 0px; left: 838.5px; top: -4.5px;\"></div><div id=\"mceResizeHandlene\" data-mce-bogus=\"all\" class=\"mce-resizehandle\" unselectable=\"true\" style=\"cursor: ne-resize; margin: 0px; padding: 0px; left: 1235.296875px; top: -4.5px;\"></div><div id=\"mceResizeHandlese\" data-mce-bogus=\"all\" class=\"mce-resizehandle\" unselectable=\"true\" style=\"cursor: se-resize; margin: 0px; padding: 0px; left: 1235.296875px; top: 293.5px;\"></div><div id=\"mceResizeHandlesw\" data-mce-bogus=\"all\" class=\"mce-resizehandle\" unselectable=\"true\" style=\"cursor: sw-resize; margin: 0px; padding: 0px; left: 838.5px; top: 293.5px;\"></div></div> </div> </section> <section id=\"section6416597692295909\"><div class=\"container\"><div class=\"row editable\" id=\"mce_31\" ><div class=\"third centerText overflowHidden\"><div><img src=\"http://templates.weesoo.com/dummy1.jpg\" class=\"fullWidth\" data-mce-src=\"http://templates.weesoo.com/dummy1.jpg\"></div><h3>Lorem ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><div><a href=\"#\" class=\"btnColor1 floatRight\" data-mce-href=\"#\">En savoir +&nbsp;</a></div></div><div class=\"third centerText overflowHidden\"><div><img src=\"http://templates.weesoo.com/dummy1.jpg\" class=\"fullWidth\" data-mce-src=\"http://templates.weesoo.com/dummy1.jpg\"></div><h3>Lorem ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><div><a href=\"#\" class=\"btnColor1 floatRight\" data-mce-href=\"#\">En savoir +</a></div></div><div class=\"third centerText overflowHidden\"><div><img src=\"http://templates.weesoo.com/dummy1.jpg\" class=\"fullWidth\" data-mce-src=\"http://templates.weesoo.com/dummy1.jpg\"></div><h3>Lorem ipsum</h3><p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><div><a href=\"#\" class=\"btnColor1 floatRight\" data-mce-href=\"#\">En savoir +</a></div></div></div></div></section>"; // 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/