Map.prototype.size

The size accessor property of {{jsxref("Map")}} instances returns the number of elements in this map.

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

```js interactive-example const map = new Map();

map.set("a", "alpha"); map.set("b", "beta"); map.set("g", "gamma");

console.log(map.size); // Expected output: 3

## Description

The value of `size` is an integer representing how many entries the `Map` object
has. A set accessor function for `size` is `undefined`; you can not change this
property.

## Examples

### Using size

```js
const myMap = new Map();
myMap.set("a", "alpha");
myMap.set("b", "beta");
myMap.set("g", "gamma");

console.log(myMap.size); // 3

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Map")}}