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

r"
"
g

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('".*\\s(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})\\s\\d+?\\s\\d+?\\s', 'g') const str = `# Bluecoat UPSTREAM Logs 2016-08-31 00:02:54 18 172.25.21.173 - - - OBSERVED "Non-Viewable/Infrastructure" - 200 TCP_HIT GET application/ocsp-response http sr.symcd.com 80 /MFYwVKADAgEAME0wSzBJMAkGBSsOAwIaBQAEFHQkFGcGn%2FXgmD9ePhproGUqVBV1BBQBWavn3ToLWaZkY9bPIAdX1ZHnagIQUufCRVii4D52%2B1NnK%2BL%2Fmg%3D%3D - - "ocspd/1.0.3" 10.222.157.10 1957 316 - 2016-08-31 00:02:54 18 172.25.19.32 - - policy_denied DENIED "Chat (IM)/SMS;Content Servers" http://im.qq.com/mobileqq 403 TCP_DENIED GET - http 203.205.144.22 80 /gchatpic_new/99787480/2125162524-3194779440-DD292643C193D85264F13026ED37A996/198 ?vuin=15929133&term=3&pictype=1003&cldver=6.5.0.443&rf=aio&msgTime=1472601651 - "QQ/6.5.0.443 CFNetwork/758.3.15 Darwin/15.4.0" 10.222.157.10 1185 421 - 2016-08-31 00:02:54 199 172.25.26.70 - - - OBSERVED "Technology/Internet" - 200 TCP_NC_MISS POST application/json;charset=utf-8 http d.applovin.com 80 /device ?device_token=MaznYs97JTiqaqEwnZGZ5u0SoeBtsuRonBn0BJmm3q8hGZZkZ8TWjSHReUJMpRCoo6knaop8PaTY2Hg-vnNcBg34k9zTsGFYDOM6zvxdBDIykMF76uM-xuc_Km4oV6e5uf6-S_X6wDyE1kpriXzu5FBhmSNn4-E-PXKNuJvyqQM= - "Dalvik/1.6.0 (Linux; U; Android 4.4.2; HTC One_E8 Build/KOT49H)" 10.222.157.10 791 1227 -`; // 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