Map() constructor

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨July 2015⁩.

The Map() constructor creates Map objects.

Syntax

new Map()
new Map(iterable)

Note: Map() can only be constructed with new. Attempting to call it without new throws a TypeError.

iterable Optional: An Array or other iterable object whose elements are key-value pairs. (For example, arrays with two elements, such as [[ 1, 'one' ],[ 2, 'two' ]].) Each key-value pair is added to the new Map.

const myMap = new Map([
  [1, "one"],
  [2, "two"],
  [3, "three"],
]);

Specification
ECMAScript® 2026 Language Specification # sec-map-constructor

This page was last modified on ⁨Jul 10, 2025⁩ by MDN contributors.