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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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HTML 

              
                <div class="container">

<h3>Collapseの使い方 ボタンで開閉</h3>
<br>
<!-- 
  data-toggle : Collapseを起動させる
  data-target : ここで指定したidとボタンを紐づける
-->
<button type="button" class="btn btn-default btn-sm" data-toggle="collapse" data-target="#demo">
  ボタンで開閉
</button>

<!-- 
  id        : ボタンと紐付いたid
  .collapse : コンテンツを隠す
  .collapse.in : コンテンツを開いた状態
-->
<div id="demo" class="collapse">
  <h3>Collapseの中身</h3>
  <ul>
    <li>リスト１</li>
    <li>リスト２</li>
    <li>リスト３</li>
  </ul>
</div>

<hr style="margin: 40px 0;">
  
<h3>Collapseの使い方 開閉するメニュー</h3>
<br>
<ul>
  <li>
    <a data-toggle="collapse" href=".collapse-menu">
      テキストリンクで開閉
    </a>
    <ul class="collapse collapse-menu">
      <li><a href="#">サブメニュー</a></li>
      <li><a href="#">サブメニュー</a></li>
      <li><a href="#">サブメニュー</a></li>
    </ul>
  </li>
</ul>

<hr style="margin: 40px 0;">

<h3>Collapseの使い方 アコーディオン</h3>
<br>
<div class="panel-group" id="test" role="tablist" aria-multiselectable="true">
  <div class="panel panel-default">
    <div class="panel-heading" role="tab" id="headingOne">
      <h4 class="panel-title">
        <a role="button" data-toggle="collapse" data-parent="#test" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
          コンテンツ１のトグルボタン
        </a>
      </h4>
    </div>
    <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne">
      <div class="panel-body">
        コンテンツ１
      </div>
    </div>
  </div>
  <div class="panel panel-default">
    <div class="panel-heading" role="tab" id="headingTwo">
      <h4 class="panel-title">
        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#test" href="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">
          コンテンツ２のトグルボタン
        </a>
      </h4>
    </div>
    <div id="collapseTwo" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingTwo">
      <div class="panel-body">
        コンテンツ２
      </div>
    </div>
  </div>
  <div class="panel panel-default">
    <div class="panel-heading" role="tab" id="headingThree">
      <h4 class="panel-title">
        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#test" href="#collapseThree" aria-expanded="false" aria-controls="collapseThree">
          コンテンツ３のトグルボタン
        </a>
      </h4>
    </div>
    <div id="collapseThree" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingThree">
      <div class="panel-body">
        コンテンツ３
      </div>
    </div>
  </div>
</div>

<hr style="margin: 40px 0;">

<h3>Collapse.jsの使い方</h3>
<br>
<a href="#" class="btn btn-default toggle-btn" data-toggle="collapse">jsで開く</a>
<div class="collapse collapse-content">
  Javascriptコンテンツ
</div>
<br>
<a href=".collapse-content2" class="btn btn-default" data-toggle="collapse">開き終わったら書き換え</a>
<div class="collapse collapse-content2">
  Javascriptコンテンツ
</div>
  
<hr style="margin: 40px 0;">

</div>
!

CSS
!

JS 

              
                //クリックしたらイベント発動
$('.toggle-btn').click(function () {
  //指定したidを閉じたり開いたり
  $('.collapse-content').collapse('toggle');
});

// 開き終わったらテキスト書き換え
$('.collapse-content2').on('shown.bs.collapse', function () {
  $(this).text('開き終わりました');
});
!
999px

Console