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Map() constructor - JavaScript | MDN
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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
js
new Map()
new Map(iterable)
Parameters
iterableOptional-
If an iterable object (such as an array) is passed, all of its elements will be added to the new
Map. Each element must be an object with two properties:0and1, which correspond to the key and value (for example,[[1, "one"],[2, "two"]]). If you don't specify this parameter, or its value isnullorundefined, the newMapis empty.
Examples
Creating a new Map
js
const myMap = new Map([
[1, "one"],
[2, "two"],
[3, "three"],
]);
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-map-constructor |
Browser compatibility
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