Set.prototype.size

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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

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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 Language Specification
# sec-get-set.prototype.size

Browser compatibility

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See also