Set.prototype.size - JavaScript | MDN
Try it
const set = new Set();
const object = {};
set.add(42);
set.add("forty two");
set.add("forty two");
set.add(object);
console.log(set.size);
// Expected output: 3
Description
The value of size is an integer representing how many entries the Set object has. A set accessor function for size is undefined; you cannot change this property.
Examples
Using size
js
const mySet = new Set();
mySet.add(1);
mySet.add(5);
mySet.add("some text");
console.log(mySet.size); // 3
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-get-set.prototype.size |