The has() method returns a boolean indicating whether an element with the specified value exists in a Set object or not.

Syntax

mySet.has(value);

Parameters

value
Required. The value to test for presence in the Set object.

Return value

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

Examples

Using the has method

var mySet = new Set();
mySet.add('foo');

mySet.has('foo');  // returns true
mySet.has('bar');  // returns false

var set1 = new Set();
var obj1 = {'key1': 1};
set1.add(obj1);

set1.has(obj1);        // returns true
set1.has({'key1': 1}); // returns false because they are different object references
set1.add({'key1': 1}); // now set1 contains 2 entries

Specifications

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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support38121311258
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support38381214258 ?

See also

Document Tags and Contributors

 Contributors to this page: wbamberg, Jun711, fscholz, jameshkramer, nmve, kdex, realityking
 Last updated by: wbamberg,