JS-053
Array Length explained in a JavaScript learning illustration — The number of elements
Beginner4 min~4 min read#array#length#arrays

Array Length

The number of elements

Goal

Learn to determine the number of elements in an array using the length property.

Explanation

  • Every array has a length property.
  • It shows the number of elements in the array.
  • length updates automatically when the array changes.
  • This property is used very often in loops.
  • length lets you quickly find the size of an array.

Analogy

If a box contains apples, you do not need to count them manually every time—length already knows how many there are.

Code

const fruits = [
  "Apple",
  "Banana",
  "Orange"
];

console.log(fruits.length);

Result: 3

Common mistake

Beginners confuse the last index with length. If length is 3, the last index is 2.

Remember

  • ✦ length shows the number of elements.
  • ✦ length is an array property.
  • ✦ length updates automatically.

Quick Quiz

What does ["A", "B", "C"].length return?

Resources