Borislav Hadzhiev
Last updated: Oct 19, 2021
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Use the size
property to get the length of a Map - map.size
. The size
property returns the number of elements in the Map
object. When accessed on an
empty Map
, the size
property returns 0
.
const map = new Map(); map.set('name', 'Tom'); map.set('age', 30); map.set('country', 'Chile'); console.log(map.size); // 👉️ 3
We used the
Map.size
property to get the number of key-value pairs the Map
stores.
The property is very similar to an array's length
property and returns an
integer representing how many items the Map
contains.
As opposed to the array's lenth
property, the size
property is read-only
and can't be changed by the user.
const map = new Map(); map.set('name', 'Tom'); console.log(map.size); // 👉️ 1 map.size = 5; console.log(map.size); // 👉️ 1
Even though we tried to set the size of the Map
, we were unable to. This is
not the case when using the array's length
property.
const arr = ['a', 'b', 'c']; console.log(arr.length); // 👉️ 3 arr.length = 1; console.log(arr.length); // 👉️ 1