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
Processing...

Test String

Code Generator

Language

Generated Code

const regex = /^(?!##?\s)([^\/\|\@\"!]*?)(##|#[@?$%]{1,3}#|\$@?\$)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^(?!##?\\s)([^\\\/\\|\\@\\"!]*?)(##|#[@?$%]{1,3}#|\\$@?\\$)', 'gm') const str = `## comment # #comment ! Basic rules ##div #@#div ##.ads #@#.ads ###ads #@##ads example.com,~example.org##div example.com,~example.org#@#div example.com,~example.org##.ads example.com,~example.org#@#.ads example.com,~example.org###ads example.com,~example.org#@##ads ! HTML filtering rules ! https://github.com/gorhill/uBlock/wiki/Static-filter-syntax#html-filters example.com##^.badstuff example.com##^script:has-text(7c9e3a5d51cdacfc) ! https://adguard.com/kb/general/ad-filtering/create-own-filters/#html-filtering-rules example.org\$\$script[data-src="banner"] example.org\$@\$script[data-src="banner"] ! CSS rules ! https://adguard.com/kb/general/ad-filtering/create-own-filters/#cosmetic-css-rules example.com#\$#div { visibility: hidden; } example.com#@\$#div { visibility: hidden; } example.com#\$#.textad { visibility: hidden; } example.com#@\$#.textad { visibility: hidden; } example.com#\$##textad { visibility: hidden; } example.com#@\$##textad { visibility: hidden; } ! Extended CSS selectors ! https://adguard.com/kb/general/ad-filtering/create-own-filters/#extended-css-selectors example.com#?#div:has(> a[target="_blank"][rel="nofollow"]) example.com#@?#div:has(> a[target="_blank"][rel="nofollow"]) example.com#?#.banner:matches-css(width: 360px) example.com#@?#.banner:matches-css(width: 360px) example.com#?##banner:matches-css(width: 360px) example.com#@?##banner:matches-css(width: 360px) example.com#\$?#div:has(> span) { display: none !important; } example.com#@\$?#div:has(> span) { display: none !important; } example.com#\$?#.banner:has(> span) { display: none !important; } example.com#@\$?#.banner:has(> span) { display: none !important; } example.com#\$?##banner:has(> span) { display: none !important; } example.com#@\$?##banner:has(> span) { display: none !important; } ! JavaScript rules ! https://adguard.com/kb/general/ad-filtering/create-own-filters/#javascript-rules ! https://adguard.com/kb/general/ad-filtering/create-own-filters/#scriptlets example.com#%#window.__gaq = undefined; example.com#@%#window.__gaq = undefined; ! Scriptlet rules example.com##+js(aopw, Fingerprint2) example.com#@#+js(aopw, Fingerprint2) example.org,example.com#%#//scriptlet("abort-on-property-read", "alert") example.com#@%#//scriptlet("abort-on-property-read")`; // 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