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

Generated Code

const regex = /(<!--\s*?export\s+?name[\:\=]([\'\"])[a-zA-Z]+?\w*?\2\s*?-->)[\s\S]+?((?=<!--\s*?export(\s+?name[\:\=]([\'\"])[a-zA-Z]+?\w*?\5)?\s*?-->)|(?:(?![\S\s])))/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(<!--\\s*?export\\s+?name[\\:\\=]([\\\'\\"])[a-zA-Z]+?\\w*?\\2\\s*?-->)[\\s\\S]+?((?=<!--\\s*?export(\\s+?name[\\:\\=]([\\\'\\"])[a-zA-Z]+?\\w*?\\5)?\\s*?-->)|(?:(?![\\S\\s])))', 'g') const str = `<body> <!-- export name:"PatientNameTh" --> <th data-fieldname="PatientPerson"> Name <span data-bind="attr: { class: sortField() == 'PatientPerson' ? 'inline-block' : 'hide' }"></span> </th> other stuff <!-- export--> <td> <span class="glyphicon glyphicon-expand"></span> <a data-bind="click: function () { \$root.loadReportSummary(PatientPerson.ID()) }"> <span data-bind="text: \$data.PatientPerson && \$data.PatientPerson.FullName"></span> </a> </td> <!-- export --> <!-- export name:"StudyTypeTh" --> <th data-fieldname="StudyType">Study Type <span data-bind="attr: { class: sortField() == 'StudyType' ? 'inline-block' : 'hide' }"></span></th> <!--export name="StudyTypeTd"--> <td data-bind="text: \$data.StudyType"></td> <!-- export --> <!-- export --> <!-- export name:"ServiceDateTh" --> <th data-fieldname="ServiceDate">Service Date<span data-bind="attr: { class: sortField() == 'ServiceDate' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"ServiceDateTd"--> <td data-bind="text: \$data.ServiceDate"></td> <!-- export name:"ExportSummaryTh" --> <th>Export Summary</th> <!-- export name:"ExportSummaryTd"--> <td><a data-bind="click: function (data) { \$root.exportReportSummary(data, PatientPerson.ID, SummaryID, !StudyExported()) }">View</a></td> <!-- export name:"PrintAllReportsTh" --> <th>Print All Reports</th> <!-- export name:"PrintAllReportsTd"--> <td><a data-bind="click: function (data) { \$root.printAllReports('/PrintReports/Reports?summaryID=' + SummaryID) }">Print</a></td> <!-- export name:"AssignStudyTh" --> <th data-fieldname="HasAssigned">Assign<span data-bind="attr: { class: sortField() == 'HasAssigned' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"AssignStudyTd"--> <td><a data-bind="visible: !\$data.StudyConfirmed, click: function () { \$root.assignStudy(\$data.SummaryID) }">Assign</a></td> <!-- export name:"FellowNameTh" --> <th data-fieldname="FellowPerson">Fellow Name<span data-bind="attr: { class: sortField() == 'FellowPerson' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"FellowNameTd"--> <td data-bind="text: \$data.FellowPerson && \$data.FellowPerson.FullName"></td> <!-- export name:"AttendingNameTh" --> <th data-fieldname="AttendingPerson">Attending Name<span data-bind="attr: { class: sortField() == 'AttendingPerson' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"AttendingNameTd"--> <td data-bind="text: \$data.AttendingPerson && \$data.AttendingPerson.FullName"></td> <!-- export name:"StudyConfirmedTh" --> <th data-fieldname="StudyConfirmed">Study Confirmed<span data-bind="attr: { class: sortField() == 'StudyConfirmed' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"StudyConfirmedTd"--> <td class="text-center"><span class="glyphicon glyphicon-ok" data-bind="visible: \$data.StudyConfirmed" /></td> <!-- export name:"StudyExportedTh" --> <th data-fieldname="StudyExported">Study Exported<span data-bind="attr: { class: sortField() == 'StudyExported' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"StudyExportedTd"--> <td class="text-center"><span class="glyphicon glyphicon-ok" data-bind="visible: \$data.StudyExported()" /></td> <!-- export name:"eMailViewTh" --> <th data-fieldname="EmailLogID">Referral<span data-bind="attr: { class: sortField() == 'EmailLogID' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"eMailViewTd"--> <td><a data-bind="visible: \$data.EmailLogID != 0" class="show-remote-modal" data-target="#myModal" data-title="Referral" data-fullscreen="true">Print</a></td> <!-- export name:"Flag0Th" --> <th data-fieldname="Flag0">Study Billed<span data-bind="attr: { class: sortField() == 'Flag0' ? 'inline-block' : 'hide' }"></span></th> <!-- export name:"Flag0Td"--> <td><a href="#" data-bind="text: \$data.Flag0() ? 'Yes' : 'No', css: { stable: \$data.Flag0(), critical: !\$data.Flag0() }, click: setUnsetStudyBilled" data-loader-message="updating..."></a></td> <!-- export --> <!-- export name:"Flag0Td"--> <td><a href="#" data-bind="text: \$data.Flag0() ? 'Yes' : 'No', css: { stable: \$data.Flag0(), critical: !\$data.Flag0() }, click: setUnsetStudyBilled" data-loader-message="updating..."></a></td> </body>)`; // 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