Map.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 Map instances returns the number of elements in this map.

Try it

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

Specification
ECMAScript Language Specification
# sec-get-map.prototype.size

Browser compatibility

BCD tables only load in the browser

See also