The has() method returns a boolean indicating whether an element with the specified key exists or not.

Syntax

myMap.has(key);

Parameters

key
Required. The key of the element to test for presence in the Map object.

Return value

Boolean
Returns true if an element with the specified key exists in the Map object; otherwise false.

Examples

Using the has method

var myMap = new Map();
myMap.set('bar', "foo");

myMap.has('bar');  // returns true
myMap.has('baz');  // returns false

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung InternetNode.js
Basic supportChrome Full support 38Edge Full support 12Firefox Full support 13IE Full support 11Opera Full support 25Safari Full support 8WebView Android Full support 38Chrome Android Full support 38Edge Mobile Full support 12Firefox Android Full support 14Opera Android Full support 25Safari iOS Full support 8Samsung Internet Android Full support Yesnodejs Full support Yes

Legend

Full support  
Full support

See also

Document Tags and Contributors

Contributors to this page: wbamberg, fscholz, jameshkramer, nmve, kdex, realityking
Last updated by: wbamberg,