Map.prototype.keys()

The keys() method returns a new Iterator object that contains the keys for each element in the Map object in insertion order.

Syntax

keys()

Return value

A new Map iterator object.

Examples

Using keys()

var myMap = new Map();
myMap.set('0', 'foo');
myMap.set(1, 'bar');
myMap.set({}, 'baz');

var mapIter = myMap.keys();

console.log(mapIter.next().value); // "0"
console.log(mapIter.next().value); // 1
console.log(mapIter.next().value); // Object

Specifications

Specification
ECMAScript Language Specification (ECMAScript)
# sec-map.prototype.keys

Browser compatibility

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See also