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

@
@
gmis

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('class="[^"]*(?<="|\\s)left-top-container(?="|\\s)[^"]*"[^<]*<h2[^>]*>(?<title>[^<]*)</h2', 'gmis') const str = `<div class="left-top-container"> <h2 itemprop="name"> Nike Magista</h2> <div class="listing_info"> <div class="list_id"><strong>List-ID: </strong>52002304 </div> <div class="list_time"> Yesterday 09:20 </div> </div> <div class="ad_images"> <!-- IMAGE GALLERY --> <div class="" id="image-gallery"> <div id="gallery-image-border"> <meta itemprop="image" content="http://img.rnudah.com/images/04/044707022491864.jpg"> <span class="trackable favourite-heart favourite-heart-empty" aria-hidden="true" data-list-id="52002304" data-company-ad="0" data-category="4160" data-region="7" data-event_type="view" data-event_name="save_favourite_ad" data-page_name="Add Favourite Ad" data-xtn2="5" data-xiti_f1="4160" data-xiti_f2="7" data-xiti_f3="2" data-xiti_f4="2" data-xiti_f5="248"></span> <div class="heart-icon-tip adview-tip"> <div class="arrow-tip"></div> <div class="tip-content"> Click on the heart to add this to your Favourite list. </div> </div> <div id="gallery-image-container"><span><a href="javascript:void(0)" onclick="gallery.nextImage()"><img src="http://img.rnudah.com/images/04/044707022491864.jpg" style="margin-top:44px;margin-left:0px"></a></span></div> </div> </div> <div id="gallery-thumbnail-containers" style="display: none"> <ul id="gallery-thumbnail-items"> <li><a href="javascript:void(0)" onclick="gallery.move('prev')" class="gallery-navigation" style="display: none;"><img src="/img/none.gif" class="sprite_view_arrow-left"></a></li> <li id="gallery-thumbnails-li"> <div id="gallery-thumbnails-ul-container"> <ul id="gallery-thumbnails" style="width: 540px;"><li data-sort="1" class="thumbnail-active"><a href="javascript:void(0)" style="margin-top: 5.5px" onmouseover="gallery.changeGalleryImage(&quot;0&quot;)"><img src="http://img.rnudah.com/thumbs/04/044707022491864.jpg"></a></li></ul> </div> </li> <li><a href="javascript:void(0)" onclick="gallery.move('next')" class="gallery-navigation" style="display: none;"><img src="/img/none.gif" class="sprite_view_arrow-right"></a></li> </ul> </div> <!-- IMAGE GALLERY --> </div> <div class="ad_info"> </div></div>`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions