JSON

JSON (JavaScript Object Notation) is a lightweight, text-based format used for storing and transporting data. It is often used when data is sent from a server to a webpage.

Example:

{
  "name": "Wariz",
  "age": 17,
  "role": "Entrepreneur"
}

JSON is the universal way to exchange structured data between different programs or over the web. It serves as a "common language" that allows software written in different languages to communicate and share information.

JSON in JavaScript

While JSON is a text format, JavaScript provides built-in methods to easily switch between JSON strings and JavaScript objects.

1. JSON.parse()

This method is used to convert a JSON string into a JavaScript object. This is necessary when you receive data from a web server and want to access or manipulate it using object properties.

const jsonString = '{"name":"Wariz", "age":17}';
const userObject = JSON.parse(jsonString);

console.log(userObject.name); // "Wariz"

2. JSON.stringify()

This method is used to convert a JavaScript object into a JSON string. This is necessary when you need to send data to a web server or store it in a text-based format.

const user = { name: "Wariz", age: 17 };
const jsonString = JSON.stringify(user);

console.log(jsonString); // '{"name":"Wariz","age":17}'

Key Rules of JSON

To keep JSON "universal" and lightweight, it follows strict formatting rules:

• Data is in name/value pairs: Keys must be wrapped in double quotes (e.g., "name").
• Commas as separators: Items in an object or array are separated by commas. Trailing commas — a comma after the last item — are not allowed.
• Curly braces hold objects: Square brackets [] hold arrays.
• Double quotes only: You cannot use single quotes for strings or keys in JSON.