How to Check the Size of a JavaScript Map ?

To check the size (number of key-value pairs) of a Map in JavaScript, you can use the size property. The size property is a property of the Map object that returns the number of elements in the Map.

Example: Here, mapSize will be equal to 3 because there are three key-value pairs in the Map.

Javascript

let myMap = new Map();

myMap.set('key1', 'value1');
myMap.set('key2', 'value2');
myMap.set('key3', 'value3');

// Check the size of the Map
let mapSize = myMap.size;

console.log(mapSize); // Output: 3

Output

3