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

/
/
g

Test String

Code Generator

Language

Generated Code

const regex = /(^|[\s:#])0(?!0{7})\d{7}([\s:a-zA-Z]|$)/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(^|[\\s:#])0(?!0{7})\\d{7}([\\s:a-zA-Z]|$)', 'g') const str = `123 234 10 DETECT: 01234561 wordfromlistc OR wordfromlistd 01234562 OR wordfromlista01234563 OR 01234567wordfromlistb DON'T DETECT: 00000000 wordfromlist OR wordfromlist 0000000 OR 00000000wordfromlist OR wordfromlist00000000 OR DON'T DETECT: 01234567- OR -01234567 OR /01234567/, etc 01234567 00000000 00000001 1505848655000-0400 12345678 {"context":{"client":{"clientName":1,"clientVersion":"2.20170920"}},"events":[{"eventTimeMs":1506022852901,"foregroundHeartbeat":{"firstActivityMs":"-1","clientDocumentNonce":"LEPgGrs4OSu6AqVj","index":"8","lastEventDeltaMs":"-1","trigger":"FOREGROUND_HEARTBEAT_TRIGGER_ON_FOREGROUND"},"context":{"lastActivityMs":"1791003"}},{"eventTimeMs":1506022855635,"foregroundHeartbeat":{"firstActivityMs":"2311","clientDocumentNonce":"LEPgGrs4OSu6AqVj","index":"9","lastEventDeltaMs":"2733","trigger":"FOREGROUND_HEARTBEAT_TRIGGER_ON_BACKGROUND"},"context":{"lastActivityMs":"861"}}],"requestTimeMs":1506022865644} {"context":{"client":{"clientName":1,"clientVersion":"2.20170920"}},"interactions":[{"attachChild":{"csn":"LBnEWZLnFcHs8wTUnKZY","parentVisualElement":{"veType":3854},"visualElements":[{"trackingParams":"CAEQumkiEwiSrfTIh7fWAhVB9pwKHVSOCQsojh4="}]},"eventTimeMs":1506023726765,"lactMs":316},{"attachChild":{"csn":"LBnEWZLnFcHs8wTUnKZY","parentVisualElement":{"veType":3854},"visualElements":[{"veType":23851,"veCounter":1}]},"eventTimeMs":1506023728252,"lactMs":1803},{"attachChild":{"csn":"LBnEWZLnFcHs8wTUnKZY","parentVisualElement":{"veType":3854},"visualElements":[{"veType":36925,"veCounter":2}]},"eventTimeMs":1506023728253,"lactMs":1804},{"attachChild":{"csn":"LBnEWZLnFcHs8wTUnKZY","parentVisualElement":{"veType":3854},"visualElements":[{"veType":28664,"veCounter":3}]},"eventTimeMs":1506023728253,"lactMs":1804},{"attachChild":{"csn":"LBnEWZLnFcHs8wTUnKZY","parentVisualElement":{"veType":3854},"visualElements":[{"veType":28662,"veCounter":4}]},"eventTimeMs":1506023728253,"lactMs":1804},{"attachChild":{"csn":"LBnEWZLnFcHs8wTUnKZY","parentVisualElement":{"veType":3854},"visualElements":[{"veType":28656,"veCounter":5}]},"eventTimeMs":1506023728253,"lactMs":1804},{"attachChild":{"csn":"MhnEWc2FDdHY8gT7qJigAw","parentVisualElement":{"veType":3832},"visualElements":[{"trackingParams":"CAEQumkiEwiSrfTIh7fWAhVB9pwKHVSOCQsojh4="}]},"eventTimeMs":1506023731445,"lactMs":560}],"requestTimeMs":1506023732093}`; // 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