-
Notifications
You must be signed in to change notification settings - Fork 22.4k
/
index.md
62 lines (44 loc) · 1.46 KB
/
index.md
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
---
title: "Request: headers property"
short-title: headers
slug: Web/API/Request/headers
page-type: web-api-instance-property
browser-compat: api.Request.headers
---
{{APIRef("Fetch API")}}
The **`headers`** read-only property of the
{{domxref("Request")}} interface contains the {{domxref("Headers")}} object associated
with the request.
## Value
A {{domxref("Headers")}} object.
## Examples
In the following snippet, we create a new request using the
{{domxref("Request.Request", "Request()")}} constructor (for an image file in the same directory as
the script), then save the request headers in a variable:
```js
const myRequest = new Request("flowers.jpg");
const myHeaders = myRequest.headers; // Headers {}
```
To add a header to the {{domxref("Headers")}} object we use
{{domxref("Headers.append")}}; we then create a new `Request` along with a
2nd init parameter, passing headers in as an init option:
```js
const myHeaders = new Headers();
myHeaders.append("Content-Type", "image/jpeg");
const myInit = {
method: "GET",
headers: myHeaders,
mode: "cors",
cache: "default",
};
const myRequest = new Request("flowers.jpg", myInit);
const myContentType = myRequest.headers.get("Content-Type"); // returns 'image/jpeg'
```
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
## See also
- [ServiceWorker API](/en-US/docs/Web/API/Service_Worker_API)
- [HTTP access control (CORS)](/en-US/docs/Web/HTTP/CORS)
- [HTTP](/en-US/docs/Web/HTTP)