JavaScript (ES2026) reference · Array Methods

JavaScript Array length Property

The number of elements in the array. Setting it shortens or extends the array.

JavaScript (ES2026) Since ES1

Syntax

array.length

An integer: one more than the highest index.

Read and set the lengthTry it yourself

const fruits = ["apple", "banana", "cherry"];
console.log(fruits.length);
fruits.length = 1;   // truncate
console.log(fruits);

Output

3
[ 'apple' ]

Check for empty, get the last elementTry it yourself

const items = [];
if (items.length === 0) console.log("empty");
console.log([1, 2, 3][[1, 2, 3].length - 1]); // last element

Output

empty
3

Version	Change
JavaScript ES1	Added

array.at() · Return the element at an index, where negative indexes count from the end: arr.at(-1) is the last element.
array.push() · Add one or more elements to the end of the array and return the new length. Changes the array in place.
JavaScript Arrays · tutorial
JavaScript Array Methods · tutorial