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]
  • Character class intersection
    [\w&&[^\d]]
  • 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 = /googletag\.defineSlot.*?'([^']*)'\);/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('googletag\\.defineSlot.*?\'([^\']*)\'\\);', 'g') const str = `googletag.defineSlot('Lorem1', [300, 100], 'div-ad-1430201576110-0'); googletag.defineSlot('Lorem2', [300, 100], 'div-ad-1442774220958-0'); googletag.defineSlot('Lorem3', [300, 100], 'div-ad-1448024965037-0'); googletag.defineSlot('Lorem4', [290, 60], 'div-ad-1429688274462-0'); googletag.defineSlot('Lorem5', [300, 200], 'div-ad-1448279284710-0'); googletag.defineSlot('Lorem6', [728, 90], 'div-ad-1389610933954-2'); googletag.defineSlot('Lorem7', [728, 90], 'div-ad-1389610933954-4'); googletag.defineSlot('Lorem8', [300, 250], 'div-ad-1389610933954-0'); googletag.defineSlot('Lorem9', [300, 250], 'div-ad-1448278717664-0'); googletag.defineSlot('Lorem10',[300, 250] 'div-ad-1425381569546-1'); googletag.defineOutOfPageSlot('Lorem11','div-ad-1424524422308-0-oop1'); googletag.defineOutOfPageSlot('Lorem12','div-ad-1424524422308-0-oop2'); googletag.defineOutOfPageSlot('Lorem13','div-ad-1389610933954-0-oop4'); googletag.defineOutOfPageSlot('Lorem14','div-ad-1389610933954-0-oop5'); googletag.defineOutOfPageSlot('Lorem15','div-ad-1389610933954-0-oop6');`; // 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