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

/
/

Test String

Code Generator

Language

Generated Code

const regex = /<REMITReceipt(.|\n)*?<errorCount>0(.|\n)*?\/REMITReceipt>/; // Alternative syntax using RegExp constructor // const regex = new RegExp('<REMITReceipt(.|\\n)*?<errorCount>0(.|\\n)*?\\\/REMITReceipt>', '') const str = ` === Receipt_20150922_REMITTable1_V1_A0000668C.SI_1.xml.asc <REMITReceipt xmlns="http://www.acer.europa.eu/REMIT/REMITReceiptSchema_V1.xsd"> <receiptTimestamp>2015-09-22T14:25:04.009+02:00</receiptTimestamp> <rrmId> <acer>A0000668C.SI</acer> </rrmId> <receiptType>validation</receiptType> <validationReceipt> <reportedFilename>20150922_REMITTable1_V1_A0000668C.SI_1.xml.asc.pgp</reportedFilename> <reportedFileChecksum>6445BEC781F4000C7F16F8685103B2D2D4DC500B</reportedFileChecksum> <errorCount>0</errorCount> <globalReceiptItem> <logicalRecordIdentifier>FWG_L_Sep_15</logicalRecordIdentifier> <logicalRecordType>CONTRACT</logicalRecordType> <status>Accepted</status> </globalReceiptItem> </validationReceipt> </REMITReceipt> === Receipt_20150922_REMITTable1_V1_A0000668C.SI_10.xml.asc <REMITReceipt xmlns="http://www.acer.europa.eu/REMIT/REMITReceiptSchema_V1.xsd"> <receiptTimestamp>2015-09-24T09:35:07.530+02:00</receiptTimestamp> <rrmId> <acer>A0000668C.SI</acer> </rrmId> <receiptType>validation</receiptType> <validationReceipt> <reportedFilename>20150922_REMITTable1_V1_A0000668C.SI_10.xml.asc.pgp</reportedFilename> <reportedFileChecksum>13F5F5D46DFC659380AD1A7982CC2F05E7E66D5E</reportedFileChecksum> <errorCount>0</errorCount> <globalReceiptItem> <logicalRecordIdentifier>4</logicalRecordIdentifier> <logicalRecordType>TRADE</logicalRecordType> <status>Accepted</status> <logicalRecordTimestamp>2015-07-14T13:12:16.223+02:00</logicalRecordTimestamp> <logicalRecordChecksum>F6A488630A39390BE48420AFFD40ED7C82D20309</logicalRecordChecksum> </globalReceiptItem> <globalReceiptItem> <logicalRecordIdentifier>3</logicalRecordIdentifier> <logicalRecordType>TRADE</logicalRecordType> <status>Accepted</status> <logicalRecordTimestamp>2015-07-14T13:12:16.223+02:00</logicalRecordTimestamp> <logicalRecordChecksum>026F539B94346186078BA906DE2F5A9F8B3E7F6E</logicalRecordChecksum> </globalReceiptItem> <globalReceiptItem> <logicalRecordIdentifier>2</logicalRecordIdentifier> <logicalRecordType>TRADE</logicalRecordType> <status>Accepted</status> <logicalRecordTimestamp>2015-07-14T08:46:40.513+02:00</logicalRecordTimestamp> <logicalRecordChecksum>0F8253A2A3C55520E4D63959E77286CA1E95622B</logicalRecordChecksum> </globalReceiptItem> <globalReceiptItem> <logicalRecordIdentifier>1</logicalRecordIdentifier> <logicalRecordType>TRADE</logicalRecordType> <status>Accepted</status> <logicalRecordTimestamp>2015-07-14T08:46:37.223+02:00</logicalRecordTimestamp> <logicalRecordChecksum>198B018687C9D97CD3EECFBACA7EA9F196B5B80F</logicalRecordChecksum> </globalReceiptItem> </validationReceipt> </REMITReceipt> =!== Receipt_20150922_REMITTable1_V1_A0000668C.SI_100.xml.asc `; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; if ((m = regex.exec(str)) !== null) { // 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