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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The get()
method of the Headers
interface returns the first value of a given header from within a Headers
object. If the requested header doesn't exist in the Headers
object, the call returns null
.
For security reasons, some headers can only be controller by the user agent. These headers include the forbidden header names and forbidden response header names.
Syntax
myHeaders.get(name);
Parameters
- name
- The name of the HTTP header whose value you want to retrieve from the
Headers
object. If the given name is not the name of an HTTP header, this method throws aTypeError
.
Returns
A ByteString
representing the value of the header retrieved.
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 get()
:
myHeaders.append('Content-Type', 'image/jpeg'); myHeaders.get('Content-Type'); // Returns 'image/jpeg'
If the header has multiple values associated with it, only the first header value will be returned:
myHeaders.append('Accept-Encoding', 'deflate'); myHeaders.append('Accept-Encoding', 'gzip'); myHeaders.get('Accept-Encoding'); // Returns 'deflate' only, as it was the first value added
Note: Use Headers.getAll
to return an array containing all values.
Specifications
Specification | Status | Comment |
---|---|---|
Fetch The definition of 'get()' in that specification. |
Living Standard |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 42 41 behind pref |
39 (39) 34 behind pref |
No support |
29 |
No support |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|
Basic support | No support | No support | No support | No support | No support | No support | No support |