JavaScript: Arrays & Objects

Arrays and objects hold almost all the data in JavaScript programs. Learn to create, read and change them, use powerful array methods such as map, filter, reduce, find and sort, work with object properties, destructuring and spread, understand references versus copies, and convert data to and from JSON. All examples tested.

Examples were tested with Node.js 22 and work in current browsers. Check MDN compatibility tables before relying on newer methods in older browsers.