---
title: Event.bubbles
slug: Web/API/Event/bubbles
translation_of: Web/API/Event/bubbles
---
<p>{{ ApiRef("DOM") }}</p>

<h3 id="Summary" name="Summary">概述</h3>

<p>表示事件是否會向上冒泡傳遞。</p>

<h3 id="語法">語法</h3>

<pre class="eval"><em>var bool</em> = event.bubbles;
</pre>

<p>回傳一個布林值，若事件會向上冒泡傳遞則回傳 <code>true</code>。</p>

<h3 id="Notes" name="Notes">備註</h3>

<p>Only certain events can bubble. Events that do bubble have this property set to <code>true</code>. You can use this property to check if an event is allowed to bubble or not.</p>

<h3 id="Example" name="Example">範例</h3>

<pre class="brush: js"> function goInput(e) {
  // checks bubbles and
  if (!e.bubbles) {
     // passes event along if it's not
     passItOn(e);
  }
  // already bubbling
  doOutput(e)
}
</pre>

<h2 id="Specifications" name="Specifications">規範</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName('DOM WHATWG', '#dom-event-bubbles', 'Event.bubbles')}}</td>
   <td>{{ Spec2('DOM WHATWG') }}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM4', '#dom-event-bubbles', 'Event.bubbles')}}</td>
   <td>{{ Spec2('DOM4') }}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM2 Events', '#Events-Event-canBubble', 'Event.bubbles')}}</td>
   <td>{{ Spec2('DOM2 Events') }}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>