To handle several pieces of data at once, JavaScript offers two essential structures: arrays and objects.

Arrays

An array stores several values in an ordered list:

const fruits = ["pomme", "banane", "cerise"];
console.log(fruits[0]); // "pomme"

You reach each item through its index, which starts at 0. You can go through an array with a loop or with the forEach method.

Objects

An object groups related information as key: value pairs:

const personne = {
  prenom: "Marie",
  age: 25
};
console.log(personne.prenom); // "Marie"

• An array is perfect for a list of similar items.
• An object describes a single entity through its properties.

Key takeaway: an array orders a list (index starting at 0), an object describes one thing through its properties (key: value).