Headers.keys()

The Headers.keys() method returns an iterator allowing to go through all keys contained in this object. The keys are ByteString objects.

Note: This method is available in Web Workers.

Syntax

headers.keys();

Return value

Returns an iterator.

Example

// Create a test Headers object
var myHeaders = new Headers();
myHeaders.append('Content-Type', 'text/xml');
myHeaders.append('Vary', 'Accept-Language');

// Display the keys
for(var key of myHeaders.keys()) {
   console.log(key); 
}

The result is:

content-type
vary

Specifications

Specification Status Comment
Fetch
The definition of 'Headers.keys() (as iterator<>)' in that specification.
Living Standard Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support451644 ?32 ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support4545 Yes4432 ?5.0

See also

Document Tags and Contributors

Contributors to this page: fscholz, jpmedley, michaelhogg, chrisdavidmills, teoli
Last updated by: fscholz,