Set.prototype.has()
The has()
method returns a boolean indicating whether an element with the specified value exists in a Set
object or not.
Syntax
has(value)
Parameters
value
-
The value to test for presence in the
Set
object.
Return value
Returns true
if an element with the specified value exists in the Set
object; otherwise false
.
Note: Technically speaking, has()
uses the Same-value-zero algorithm to determine whether the given element is found.
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
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
has |
38 |
12 |
13 |
11 |
25 |
8 |
38 |
38 |
14 |
25 |
8 |
3.0 |
See also
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/has