---
title: Notification.permission
slug: Web/API/notification/permission
translation_of: Web/API/Notification/permission
---
<p>{{APIRef("Web Notifications")}}</p>

<p><code>Notification 的只读属性 permission 用来表明用户是否允许当前域显示Web Notification. </code></p>

<p>{{AvailableInWorkers}}</p>

<h2 id="Syntax" name="Syntax">Syntax</h2>

<pre class="syntaxbox">var <em>permission</em> = Notification.permission;</pre>

<h3 id="Return_Value" name="Return_Value">Value</h3>

<p>permission 的类型为 {{domxref("DOMString")}} . 该属性的可能值为:</p>

<ul>
 <li><code>granted</code>: 用户已经明确的授予了显示通知的权限。.</li>
 <li><code>denied</code>: 用户已经明确的拒绝了显示通知的权限。</li>
 <li><code>default</code>: 用户还未被询问是否授权; 这种情况下权限将视为 <code>denied</code>.</li>
</ul>

<h2 id="Examples">Examples</h2>

<p>下面的代码片段详细的说明了，当你首次检查浏览器是否支持Notification，然后检查当前域是否被授予了发送Notification的权限，并且在发送一个通知前进行请求的用法．</p>

<pre class="brush: js">function notifyMe() {
  // Let's check if the browser supports notifications
  if (!("Notification" in window)) {
    console.log("This browser does not support desktop notification");
  }

  // Let's check whether notification permissions have alredy been granted
  else if (Notification.permission === "granted") {
    // If it's okay let's create a notification
    var notification = new Notification("Hi there!");
  }

  // Otherwise, we need to ask the user for permission
  else if (Notification.permission !== 'denied' || Notification.permission === "default") {
    Notification.requestPermission(function (permission) {
      // If the user accepts, let's create a notification
      if (permission === "granted") {
        var notification = new Notification("Hi there!");
      }
    });
  }

  // At last, if the user has denied notifications, and you
  // want to be respectful there is no need to bother them any more.
}</pre>

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

<table>
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName("Web Notifications","#dom-notification-permission","permission")}}</td>
   <td>{{Spec2('Web Notifications')}}</td>
   <td>Living standard</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

{{Compat("api.Notification.permission")}}

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Web/API/Notifications_API/Using_the_Notifications_API">Using the Notifications API</a></li>
 <li>{{domxref("Permissions_API","Permissions API")}}</li>
</ul>