Set.prototype.size

The size accessor property of {{jsxref("Set")}} instances returns the number of (unique) elements in this set.

{{InteractiveExample("JavaScript Demo: Set.prototype.size")}}

```js interactive-example 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#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Set")}}