📎 This article includes 2 downloadable practice files ↓

📘 JavaScript Beginner Course · Lesson 6 of 8

“`javascript
const order = { id: “SO-1001”, customer: { name: “Iyer Stores”, city: “Chennai” },
items: [{ p: “Laptop”, q: 2, r: 42000 }] };
order.customer.name; // “Iyer Stores”
const json = JSON.stringify(order); // text, to save or send
const back = JSON.parse(json); // object again
const { customer: { city } } = back; // destructuring
“`

JSON

JavaScript Object Notation is plain text that looks like these objects. APIs, config files and many exports use it. Keys must be in double quotes; no trailing commas.

Useful helpers

Object.keys(o), Object.values(o), Object.entries(o); the optional chaining order.customer?.gstin returns undefined instead of crashing when a property is missing.

Practice

Run the script, then add a second item and print the order total.