The size accessor property of Map instances returns the number of elements in this map.

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

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

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

Specifications

Browser compatibility

See also

• Map