Set.prototype.add()

The add() method of Set instances inserts the specified value into this set, if it is not already present.

Try it

const set = new Set();

set.add(42);
set.add(42);
set.add(13);

for (const item of set) {
  console.log(item);
  // Expected output: 42
  // Expected output: 13
}

Syntax

js
add(value)

Parameters

value

The value to add to the Set object. Objects are compared by reference, not by value.

Return value

The Set object.

Examples

undefined

Using add()

js
const mySet = new Set();

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

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

Specifications

See also