Headers.keys()

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

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 compatibility

See also

• ServiceWorker API
• HTTP access control (CORS)
• HTTP