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

/
/
gi

Test String

Code Generator

Language

Generated Code

const regex = /(\[(?<first>icode|quote|code)[^\]]*?\](?:[\s]*?.)*?[\s]*?\[\/(?:\k<first>)\])/gi; // Alternative syntax using RegExp constructor // const regex = new RegExp('(\\[(?<first>icode|quote|code)[^\\]]*?\\](?:[\\s]*?.)*?[\\s]*?\\[\\\/(?:\\k<first>)\\])', 'gi') const str = `[quote]Id in voluptatem [U]odit itaque[/U] ea. Qui eum [URL='http://#']fugiat[/URL] doloribus dicta nisi. [icode]Exercitationem sit error maxime aperiam quaerat hic deleniti quidem[/icode]. Totam laudantium aut quia. "Sint ut ut vel ratione," Qui porro eaque enim fugit. [/quote] Quam consequatur consequatur voluptate molestiae explicabo [icode]qui consectetur[/ICODE], "Voluptatem saepe [b]ex adipisci aut est rem[/b]." Numquam a cupiditate non officiis sed aspernatur. [quote="Lorem Ipsum, post: 12345, member: 123"]Aut deleniti nihil sit. Saepe dolorem blanditiis nemo. Ab et cumque nesciunt. Quos velit vel nam porro.[/quote] [spoiler="Name"]Unde et eius tempore consequatur. "Vitae est ut et," est numquam.""[/spoiler] Quo <span style="color: #24c4f9"><b>suscipit</b></span> sequi id ratione "doloribus omnis". <span style="font-family: 'Lucida Console'"><span style="font-size: 18px">Lorem ipsum dolor sit amet, consectetur adipiscing elit. " Maecenas sed nibh ac neque semper finibus. Saepe dolorem blanditiis nemo. " </b></span> [CODE=html] Vivamus hendrerit augue "volutpat", consequat risus sed, dignissim orci. Fusce sed pellentesque ipsum. Suspendisse nisi odio, gravida sed leo ut, tristique posuere felis. [/CODE] Ut tempor vestibulum viverra. Vivamus imperdiet fringilla est fermentum facilisis. Quisque nec massa sit amet augue eleifend condimentum at nec arcu. [CENTER][B]Quam consequa[/B] "tur c[I]onse[/I]quatur". Eum molestias "et" doloribus et rem dolorem vero qui.[/CENTER]`; // 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