Set.prototype[Symbol.iterator]() - JavaScript | MDN

Try it

const set = new Set();

set.add(42);
set.add("forty two");

const iterator = set[Symbol.iterator]();

console.log(iterator.next().value);
// Expected output: 42

console.log(iterator.next().value);
// Expected output: "forty two"

Syntax

Parameters

None.

Return value

The same return value as Set.prototype.values(): a new iterable iterator object that yields the values of the set.

Examples

Iteration using for...of loop

Note that you seldom need to call this method directly. The existence of the [Symbol.iterator]() method makes Set objects iterable, and iterating syntaxes like the for...of loop automatically call this method to obtain the iterator to loop over.

js

const mySet = new Set();
mySet.add("0");
mySet.add(1);
mySet.add({});

for (const v of mySet) {
  console.log(v);
}

Manually hand-rolling the iterator

You may still manually call the next() method of the returned iterator object to achieve maximum control over the iteration process.

js

const mySet = new Set();
mySet.add("0");
mySet.add(1);
mySet.add({});

const setIter = mySet[Symbol.iterator]();

console.log(setIter.next().value); // "0"
console.log(setIter.next().value); // 1
console.log(setIter.next().value); // {}

Specifications

Specification
ECMAScript® 2027 Language Specification
# sec-set.prototype-%symbol.iterator%

Browser compatibility

See also

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