mozilla

Set.prototype.has()

This is a new technology, part of the ECMAScript 2015 (ES6) standard .
This technology's specification has been finalized, but check the compatibility table for usage and implementation status in various browsers.

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

Specifications

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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 38 13.0 (13.0) 11 25 7.1
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support Not supported 38 13.0 (13.0) Not supported Not supported 8

See also

Document Tags and Contributors

Contributors to this page: fscholz, realityking
Last updated by: fscholz,