map.set

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

Syntax

myMap.set(key, value);

Parameters

key

Required. The key of the element to add to the Map object.

value

Required. The value of the element to add to the Map object.

Return value

The Map object.

Examples

Using the set method

var 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');

Specifications

Specification	Status	Comment
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Map.prototype.set' in that specification.	Standard	Initial definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'Map.prototype.set' in that specification.	Draft

Browser compatibility

Compatibility notes

• Prior to Firefox 33 (Firefox 33 / Thunderbird 33 / SeaMonkey 2.30), Map.prototype.set returned undefined and was not chainable. This has been fixed (bug 1031632). The behavior can be found in Chrome/v8 as well (issue). This behavior can also be found in IE11.

See also

• Map
• Map.prototype.get()
• Map.prototype.has()