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. In this particular case, this iterator object is also an iterable, so a for...of loop can be used.
Try it
Syntax
keys()
Return value
A new Map iterator object.
Examples
Using keys()
const myMap = new Map();
myMap.set("0", "foo");
myMap.set(1, "bar");
myMap.set({}, "baz");
const mapIter = myMap.keys();
console.log(mapIter.next().value); // "0"
console.log(mapIter.next().value); // 1
console.log(mapIter.next().value); // {}
Specifications
| Specification |
|---|
| ECMAScript Language Specification # sec-map.prototype.keys |
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