JSON in JavaScript

What Is JSON?

JSON stands for JavaScript Object Notation.

JSON is a simple format used to store and exchange data.

It is commonly used when sending data between a server and a web application.

For example, when we fetch data from an API, the data is often sent in JSON format.

Example of JSON

{
    "name": "Lokesh",
    "age": 22,
    "course": "Java Full Stack"
}

JSON stores data using key-value pairs.

For example:

• "name" is a key.
• "Lokesh" is its value.

JSON vs JavaScript Object

JSON looks similar to a JavaScript object, but there are some differences.

JavaScript Object

let user = {
    name: "Lokesh",
    age: 22
};

JSON

{
    "name": "Lokesh",
    "age": 22
}

One important difference is that JSON requires property names to be written with double quotes.

JSON.stringify()

JSON.stringify() converts a JavaScript object into a JSON string.

let user = {
    name: "Lokesh",
    age: 22
};

let jsonData = JSON.stringify(user);

console.log(jsonData);

Output:

{"name":"Lokesh","age":22}

This is useful when we need to send JavaScript data in JSON format.

JSON.parse()

JSON.parse() converts a JSON string into a JavaScript object.

let jsonData = '{"name":"Lokesh","age":22}';

let user = JSON.parse(jsonData);

console.log(user.name);

Output:

Lokesh

Now, we can access the data like a normal JavaScript object.

JSON and APIs

JSON is commonly used with APIs.

For example:

fetch("https://dummyjson.com/products")
    .then((response) => response.json())
    .then((data) => {
        console.log(data);
    });

Here:

1. fetch() requests data from the API.
2. response.json() reads and parses the JSON response.
3. We can then use the data in JavaScript.

Important Points to Remember

• JSON stands for JavaScript Object Notation.
• JSON is used to store and exchange data.
• JSON uses key-value pairs.
• JSON.stringify() converts a JavaScript value into a JSON string.
• JSON.parse() converts a JSON string into a JavaScript value.
• JSON is commonly used when working with APIs.