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.
Living Standard  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic Support38121311257.1
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support3838121311258

See also

Document Tags and Contributors

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