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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

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 45 16 44 ? 32 ?
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support 45 45 Yes 44 32 ? 5.0

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Headers/keys