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
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | ? | 44 (44) | ? | ? | ? |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|
| Basic support | ? | ? | 44.0 (44) | (Yes) | ? | ? | ? |
See also
Document Tags and Contributors
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Contributors to this page:
chrisdavidmills,
teoli
Last updated by:
chrisdavidmills,