---
title: Response
slug: Web/API/Response
translation_of: Web/API/Response
---
<div>{{APIRef("Fetch API")}}</div>

<p><a href="/en-US/docs/Web/API/Fetch_API">Fetch API</a>  的 <strong><code>Response</code></strong> 介面代表了一個請求會返回的回應。</p>

<p>你可以用 {{domxref("Response.Response()")}} 建構子創建一個新的 <code>Response</code>物件。但實務上碰到 Response 物件的時機，比較常出現在進行了一個 API 操作後，得到返回的 Response 物件。舉例而言，使用 service worker {{domxref("Fetchevent.respondWith")}} 或是使用單純的{{domxref("GlobalFetch.fetch()")}}。</p>

<h2 id="建構子">建構子</h2>

<dl>
 <dt>{{domxref("Response.Response","Response()")}}</dt>
 <dd>創建一個新的  <code>Response</code> 物件。</dd>
</dl>

<h2 id="屬性">屬性</h2>

<dl>
 <dt>{{domxref("Response.headers")}} {{readonlyinline}}</dt>
 <dd>包含與此 response 相關的 {{domxref("Headers")}} 物件。</dd>
 <dt>{{domxref("Response.ok")}} {{readonlyinline}}</dt>
 <dd>無論此 response 是不是成功 ( 狀態碼 200-299 ) 都會包含一個 boolean 狀態。</dd>
 <dt>{{domxref("Response.redirected")}} {{ReadOnlyInline}}</dt>
 <dd>指出此 response 是不是個重新導向的結果，如果是的話，代表此 URL 具有一個以上的入口。</dd>
 <dt>{{domxref("Response.status")}} {{readonlyinline}}</dt>
 <dd>包含此  response  的狀態碼(例如：成功時為 <code>200</code> )。</dd>
 <dt>{{domxref("Response.statusText")}} {{readonlyinline}}</dt>
 <dd>包含狀態碼所對應的狀態文字 (例如： <code>OK</code> 對應 <code>200</code>)。</dd>
 <dt>{{domxref("Response.type")}} {{readonlyinline}}</dt>
 <dd>包含此 response 的類型 (例如： <code>basic</code>, <code>cors</code>)。</dd>
 <dt>{{domxref("Response.url")}} {{readonlyinline}}</dt>
 <dd>包含此 response 的 URL。</dd>
 <dt>{{domxref("Response.useFinalURL")}}</dt>
 <dd>包含一個 boolean 狀態，指出此 URL 是否為此 response 的最後一步。</dd>
</dl>

<p><code>Response</code> 實做了{{domxref("Body")}}, 所以它另有以下可用的屬性：</p>

<dl>
 <dt>{{domxref("Body.body")}} {{readonlyInline}}</dt>
 <dd>A simple getter used to expose a {{domxref("ReadableStream")}} of the body contents.</dd>
 <dt>{{domxref("Body.bodyUsed")}} {{readonlyInline}}</dt>
 <dd>Stores a {{domxref("Boolean")}} that declares whether the body has been used in a response yet.</dd>
</dl>

<h2 id="方法">方法</h2>

<dl>
 <dt>{{domxref("Response.clone()")}}</dt>
 <dd>建立一份  <code>Response</code> 的複製物件。</dd>
 <dt>{{domxref("Response.error()")}}</dt>
 <dd>Returns a new <code>Response</code> object associated with a network error.</dd>
 <dt>{{domxref("Response.redirect()")}}</dt>
 <dd>Creates a new response with a different URL.</dd>
</dl>

<p><code>Response</code> implements {{domxref("Body")}}, so it also has the following methods available to it:</p>

<dl>
 <dt>{{domxref("Body.arrayBuffer()")}}</dt>
 <dd>Takes a {{domxref("Response")}} stream and reads it to completion. It returns a promise that resolves with an {{domxref("ArrayBuffer")}}.</dd>
 <dt>{{domxref("Body.blob()")}}</dt>
 <dd>Takes a {{domxref("Response")}} stream and reads it to completion. It returns a promise that resolves with a {{domxref("Blob")}}.</dd>
 <dt>{{domxref("Body.formData()")}}</dt>
 <dd>Takes a {{domxref("Response")}} stream and reads it to completion. It returns a promise that resolves with a {{domxref("FormData")}} object.</dd>
 <dt>{{domxref("Body.json()")}}</dt>
 <dd>Takes a {{domxref("Response")}} stream and reads it to completion. It returns a promise that resolves with the result of parsing the body text as {{jsxref("JSON")}}.</dd>
 <dt>{{domxref("Body.text()")}}</dt>
 <dd>Takes a {{domxref("Response")}} stream and reads it to completion. It returns a promise that resolves with a {{domxref("USVString")}} (text).</dd>
</dl>

<h2 id="範例">範例</h2>

<p>在<a href="https://github.com/mdn/fetch-examples/tree/master/basic-fetch">基本 fetch 範例</a> (<a href="http://mdn.github.io/fetch-examples/basic-fetch/">run example live</a>) 中，我們使用<span style="font-size: 1rem; letter-spacing: -0.00278rem;"> </span><code style="font-size: 1rem; letter-spacing: -0.00278rem;">fetch()</code><span style="font-size: 1rem; letter-spacing: -0.00278rem;"> 呼叫來得到圖片，並使用 {{htmlelement("img")}} tag 顯示。 這裡的</span><code style="font-size: 1rem; letter-spacing: -0.00278rem;">fetch()</code><span style="font-size: 1rem; letter-spacing: -0.00278rem;"> 呼叫返回了一個 promise，它使用與資源 fetch 操作有關的 </span><code style="font-size: 1rem; letter-spacing: -0.00278rem;">Response</code><span style="font-size: 1rem; letter-spacing: -0.00278rem;"> 進行解析。你可能有發現，由於我們要求的是一張圖片，所以需要用 {{domxref("Body.blob")}} ({{domxref("Response")}} 時做了 body) 讓 response 有正確的 MIME 類型。</span></p>

<pre class="brush: js">const image = document.querySelector('.my-image');
fetch('flowers.jpg').then(function(response) {
  return response.blob();
}).then(function(blob) {
  const objectURL = URL.createObjectURL(blob);
  image.src = objectURL;
});</pre>

<p>除此之外，你也能用 {{domxref("Response.Response()")}} 建構子去建立自己的客製化 <code>Response</code> 物件：</p>

<pre class="brush: js">const response = new Response();</pre>

<h2 id="規範">規範</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Fetch','#response-class','Response')}}</td>
   <td>{{Spec2('Fetch')}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="瀏覽器相容性">瀏覽器相容性</h2>



<p>{{Compat("api.Response")}}</p>

<h2 id="參考">參考</h2>

<ul>
 <li><a href="/en-US/docs/Web/API/ServiceWorker_API">ServiceWorker API</a></li>
 <li><a href="/en-US/docs/Web/HTTP/Access_control_CORS">HTTP access control (CORS)</a></li>
 <li><a href="/en-US/docs/Web/HTTP">HTTP</a></li>
</ul>