JavaScript JSON

JSON, or JavaScript Object Notation, is a lightweight data-interchange format. It's a way to organize and transport data that's easy for humans to read and write, and easy for machines to parse and generate. Despite its name, JSON is language-independent and is used by many programming languages, not just JavaScript.

What is JSON?

JSON stands for JavaScript Object Notation.
It is a lightweight data format used to store and exchange data.
It is easy for humans to read and write, and easy for machines to parse and generate.

It is often used to send data between a client (browser) and a server.

JSON Syntax

JSON is written in key-value pairs inside .

Keys are always strings (enclosed in double quotes " ").
Values can be: string, number, object, array, boolean, or null.

{
  "name": "Alice",
  "age": 25,
  "isStudent": false,
  "hobbies": ["reading", "gaming", "coding"],
  "address": {
    "city": "New York",
    "zip": "10001"
  }
}

JSON in JavaScript

JSON is very similar to JavaScript objects, but there are differences:

JSON keys must be in double quotes.
JSON does not support functions or comments.

Converting between JSON and JavaScript objects

1️. JSON to JavaScript Object

Use JSON.parse() to convert JSON string → JavaScript object.

const jsonString = '{"name":"Alice","age":25}';
const obj = JSON.parse(jsonString);

console.log(obj.name); // Alice
console.log(obj.age);  // 25

2️. JavaScript Object to JSON

Use JSON.stringify() to convert JavaScript object → JSON string.

const person = {
  name: "Bob",
  age: 30
};

const jsonStr = JSON.stringify(person);
console.log(jsonStr); // {"name":"Bob","age":30}