set.add

The add() method appends a new element with a specified value to the end of a Set object.

Syntax

mySet.add(value);

Parameters

value

Required. The value of the element to add to the Set object.

Return value

The Set object.

Examples

Using the add method

var mySet = new Set();

mySet.add(1);
mySet.add(5).add('some text'); // chainable

console.log(mySet);
// Set [1, 5, "some text"]

Specifications

Specification	Status	Comment
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Set.prototype.add' in that specification.	Standard	Initial definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'Set.prototype.add' in that specification.	Draft

Browser compatibility

Firefox-specific notes

• Prior to Firefox 33 (Firefox 33 / Thunderbird 33 / SeaMonkey 2.30), Set.prototype.add returned undefined and was not chainable. This has been fixed (bug 1031632). The behavior can be found in Chrome/v8 as well (issue).

See also

• Set
• Set.prototype.delete()
• Set.prototype.has()