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

`
`
gm

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('Content-ID:[\\s\\S].+?c4d149e6-3f6a-4aa8-bd07-244c92bdc262-2@cxf.apache.org[\\s\\S]*?>([\\s\\S]*?)--uuid', 'gm') const str = `HTTP/1.1 200 OK Date: ... Server: ..... Set-Cookie: ....; Path=/; HttpOnly Set-Cookie: ...; Path=/; HttpOnly Content-Type: multipart/related; type="application/xop+xml"; boundary="uuid:0f7fa750-c317-4039-897a-a90685b00d29"; start="<...>"; start-info="text/xml" Keep-Alive: timeout=5, max=99 Connection: Keep-Alive Transfer-Encoding: chunked --uuid:0f7fa750-c317-4039-897a-a90685b00d29 Content-Type: application/xop+xml; charset=UTF-8; type="text/xml"; Content-Transfer-Encoding: binary Content-ID: <root.message@cxf.apache.org> <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><ns2:downloadAttachResponse xmlns:ns2="http://..../"><return><errStr></errStr><result>0</result><contentFile><xop:Include xmlns:xop="http://www.w3.org/2004/08/xop/include" href="cid:c4d149e6-3f6a-4aa8-bd07-244c92bdc262-2@cxf.apache.org"/></contentFile></return></ns2:downloadAttachResponse></soap:Body></soap:Envelope> --uuid:0f7fa750-c317-4039-897a-a90685b00d29 Content-Type: application/octet-stream Content-Transfer-Encoding: binary Content-ID: <c4d149e6-3f6a-4aa8-bd07-244c92bdc262-2@cxf.apache.org> %PDF-1.4 ... LOTS OF BINARY CODE HERE FOR THE PDF --uuid:0f7fa750-c317-4039-897a-a90685b00d29--" `; // 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