Map.prototype.size - JavaScript | MDN

Try it

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

Specification
ECMAScript® 2027 Language Specification
# sec-get-map.prototype.size

Browser compatibility

See also

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