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HTML

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Adding Classes

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About the <head>

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CSS

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CSS Base

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                <main>
  <h1>Auto tạo menu cho H2, H3</h1>
  <p>Nhấn để scroll đến Heading</p>
  <div class="js-table-of-content table-of-content"></div>

  <div class="page-content">
    <h2>Heading 1 - H2</h2>
    <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
    <h2>Heading 2 - H2</h2>
    <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
    <h2>Heading 3 - H2</h2>
    <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
    <h3>Heading 4 - H3</h3>
    <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
    <h2>Heading 5 - H2</h2>
    <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>
  </div>
</main>
!

CSS 

              
                @import url(https://fonts.googleapis.com/css?family=Roboto);

body {
  font-family: Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.57;
  background: #FFFF40;
  min-height: 100%;
}

main {
  background: #fff;
  max-width: 1024px;
  margin: auto;
  padding: 25px;
  border-radius: 5px;
}

.table-of-content {
  background: #ddd;
  padding: 15px;
  border-radius: 5px;
  .title-group {
    .title {
      font-size: 120%;
      font-weight: bold;
    }
  }

  .list {
    .heading-3 {
      padding-left: 15px;
    }
  }
}
!

JS 

              
                (function ($) {});
setList();

function setList() {
  var tabId = 0;
  // $(".js-table-of-content").remove();

  var segments = [],
    arrayId = [],
    html =
      '<div class="title-group"><span class="title">MỤC LỤC</span></div><div class="list js-list">';

  $(".page-content h2, .page-content h3").each(function () {
    var data = getData(this, segments),
      hId = "tab" + tabId + "_h" + data.hLevel + segments.join("_");

    // add Level to array
    arrayId.push(data.hLevel);

    // Set data
    segments = data.segments;
    html +=
      '<p class="heading-' +
      data.hLevel +
      '"><a href="#' +
      hId +
      '">' +
      data.hText +
      "</a></p>";

    // Add ID to element
    $(this).attr("id", hId);
  });

  html += "</div>";

  console.log(html);

  // Append to HTML
  if (arrayId.length) {
    $(".js-table-of-content").append(html);
  }
}

// Get data heading
function getData(element, segments) {
  var hLevel = parseInt(element.nodeName.substring(1), 10),
    hIndex = parseInt(element.nodeName.substring(1)) - 1,
    hText = $(element).text();

  // Just found a levelUp event
  if (segments.length - 1 > hIndex) {
    segments = segments.slice(0, hIndex + 1);
  }

  // Just found a levelDown event
  if (segments[hIndex] == undefined) {
    segments[hIndex] = 0;
  }

  // count + 1 at current level
  segments[hIndex]++;

  return {
    hLevel: hLevel,
    hIndex: hIndex,
    hText: hText,
    segments: segments
  };
}
!
999px

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