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');

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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support381213111258
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support38381214258 Yes

1. Returns 'undefined' instead of the 'Map' object.

See also

Document Tags and Contributors

Last updated by: wbamberg,