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

/
/

Test String

Code Generator

Language

Generated Code

const regex = /<div id="pageContent">[\s\S]*<div id="pageContent">/; // Alternative syntax using RegExp constructor // const regex = new RegExp('<div id="pageContent">[\\s\\S]*<div id="pageContent">', '') const str = ` "HTML Tidy for Mac OS X (vers 31 October 2006 - Apple Inc. build 15.15), see www.w3.org"> <title>02.00: Page 1</title> <meta charset="utf-8"> <script type="text/javascript"> var pg_csslibs = []; // CSS Libs for this Page var pg_jslibs = []; // JS Libs for this Page </script> <script src="../../global/js/settings.js" id="settingJS" type= "text/javascript"> </script> </head> <body> <div id="pageContent"> <!-- CONTENT GOES HERE --> <div id="pageContent"> <div> <p><a href="pop/02_00_01/02_00_01_pop01.htm" class= "modal-pop"><strong>Print</strong></a> the Carousel of Progress Checklist provided below to keep track of your progress through the <span class="lang" data-term= "module_name">module</span>. It is important that you read each page and complete all practice activities in every <span class="lang" data-term="lesson_name`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; if ((m = regex.exec(str)) !== null) { // 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