Headers.getAll() - Web API 接口参考 编辑

这是一个实验中的功能
此功能某些浏览器尚在开发中，请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订，所以在未来版本的浏览器中该功能的语法和行为可能随之改变。

getAll() 方法会以数组形式返回指定header的所有值. 如果指定的header未存在,则返回一个空数组.

Note:出于安全原因, 部分头信息只能被用户代理控制. 这些头信息包括 forbidden header names  和 forbidden response header names.

Syntax

myHeaders.getAll(name);

Parameters

name

需检索的HTTP header名称. 如果HTTP header中不存在指定名称则抛出一个 TypeError.

Returns

An Array containing a ByteString sequence representing the values of the retrieved header.

Example

Creating an empty Headers object is simple:

var myHeaders = new Headers(); // Currently empty

You could add a header to this using Headers.append, then retrieve it using getAll():

myHeaders.append('Content-Type', 'image/jpeg');
myHeaders.getAll('Content-Type'); // Returns [ "image/jpeg" ]

If the header has multiple values associated with it, the array will contain all the values, in the order they were added to the Headers object:

myHeaders.append('Accept-Encoding', 'deflate');
myHeaders.append('Accept-Encoding', 'gzip');
myHeaders.getAll('Accept-Encoding'); // Returns [ "deflate", "gzip" ]

Note: Use Headers.get to return only the first value added to the Headers object.

Specifications

Specification	Status	Comment
Fetch getAll()	Living Standard

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

• Desktop
• Mobile

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	42 41 behind pref	39 (39) 34 behind pref	未实现	29 28 behind pref	未实现

Feature	Android	Firefox Mobile (Gecko)	Firefox OS (Gecko)	IE Phone	Opera Mobile	Safari Mobile	Chrome for Android
Basic support	未实现	未实现	未实现	未实现	未实现	未实现	未实现

See also

• ServiceWorker API
• HTTP access control (CORS)
• HTTP