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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 ⁨October 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

keys()

Parameters

None.

Return value

Returns an iterator.

Examples

// 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