Headers: keys() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2017.
Note: This feature is available in Web Workers.
The Headers.keys()
method returns an
iterator
allowing to go through all keys contained
in this object. The keys are String
objects.
Syntax
js
keys()
Parameters
None.
Return value
Returns an iterator
.
Examples
js
// Create a test Headers object
const myHeaders = new Headers();
myHeaders.append("Content-Type", "text/xml");
myHeaders.append("Vary", "Accept-Language");
// Display the keys
for (const key of myHeaders.keys()) {
console.log(key);
}
The result is:
content-type vary
Browser compatibility
Report problems with this compatibility data on GitHubdesktop | mobile | server | ||||||||||||
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keys |
Legend
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- Full support
- Full support
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.