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Map() constructor

The Map() constructor creates Map objects.

Syntax

js
new Map()
new Map(iterable)

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

Parameters

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.

Examples

Creating a new Map

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

Specifications

Specification
ECMAScript Language Specification
# sec-map-constructor

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android Deno Node.js
Map 38 12 13 25 8 38 14 25 8 3.0 38 1.0 0.12.0
iterable_allowed 38 12 13 25 9 38 14 25 9 3.0 38 1.0 0.12.0
new_required 38 12 42 25 9 38 42 25 9 3.0 38 1.0 0.12.0
null_allowed 38 12 37 25 9 38 37 25 9 3.0 38 1.0 0.12.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/Map