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Map.prototype.set()

The set() method adds or updates an entry in a Map object with a specified key and a value.

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Syntax

set(key, value)

Parameters

key: The key of the element to add to the Map object. The key may be any JavaScript type (any primitive value or any type of JavaScript object).
value: The value of the element to add to the Map object. The value may be any JavaScript type (any primitive value or any type of JavaScript object).

Return value

The Map object.

Examples

Using set()

const myMap = new Map();

// Add new elements to the map
myMap.set('bar', 'foo');
myMap.set(1, 'foobar');

// Update an element in the map
myMap.set('bar', 'baz');

Using the set() with chaining

Since the set() method returns back the same Map object, you can chain the method call like below:

// Add new elements to the map with chaining.
myMap.set('bar', 'foo')
  .set(1, 'foobar')
  .set(2, 'baz');

Specifications

Specification
ECMAScript Language Specification # sec-map.prototype.set

Browser compatibility

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	Deno	Node.js
`set`	38	12	13	11 Returns 'undefined' instead of the 'Map' object.	25	8	38	38	14	25	8	3.0	1.0	0.12.0 0.10.0