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web api instance method

Headers: keys() method

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Available in 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

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also