Array Basics

Array Basics

An array is an ordered list of values. It is one of the most used data structures in JavaScript.

Creating an array

let fruits = ["apple", "banana", "cherry"];
let numbers = [1, 2, 3, 4, 5];
let mixed = ["hello", 42, true];

Arrays can hold anything

An array can mix strings, numbers, booleans, objects, and even other arrays.

Access items by index

Indexes start at 0:

fruits[0]; // "apple"
fruits[1]; // "banana"
fruits[2]; // "cherry"

Change an item

fruits[1] = "blueberry";

The length property

fruits.length; // 3

The last item

fruits[fruits.length - 1]; // last element

TL;DR

• Arrays are ordered lists in square brackets.
• Indexes start at 0.
• Use [index] to read or write items.
• .length gives the number of items.