JSON (JavaScript Object Notation) is a lightweight data format for storing and exchanging data. It is easy to read and write for humans and machines. JSON is commonly used in APIs to send and receive data between a client and a server.

Sample:

{
 "name": "Ashutosh",
 "age": 25,
 "isDeveloper": true,
 "skills": ["JavaScript", "C#", "SQL"],
 "address": {
   "city": "Prayagraj",
   "country": "India"
 },
 "experience": null
}

JSON Data Types

JSON supports six data types:

A. JSON String (Text Data)

Strings in JSON must be enclosed in double quotation marks (" "), while single quotation marks (' ') are also allowed in JavaScript.

{
 "language": "JavaScript"
}

B. JSON Number (Integer & Floating Point)

JSON supports integers and floating-point numbers without quotation marks.

{
 "age": 25,
 "price": 99.99
}

C. JSON Boolean (true or false)

The boolean datatype values ​​represent true or false.

{
 "isStudent": false,
 "isVerified": true
}

D. JSON Array (List of Values)

An array in JSON is an ordered list of values. It can contain strings, numbers, objects, or other arrays.

{
 "skills": ["JavaScript", "C#", "SQL"]
}

E. JSON Object (Key-Value Pairs)

An object is a collection of key-value pairs, similar to a JavaScript object.

{
 "address": {
   "city": "Prayagraj",
   "country": "India"
 }
}

F. JSON Null (Empty Value)

The null represents an empty or missing value.

{
 "experience": null
}

Parsing and Stringifying JSON in JavaScript

Convert JSON to JavaScript Object (JSON.parse())

let jsonString = '{"name": "Ashutosh", "age": 25, "isDeveloper": true}';
let jsonObject = JSON.parse(jsonString);
console.log(jsonObject.name); // Output: Ashutosh

Convert JavaScript Object to JSON (JSON.stringify())

let user = { name: "Ashutosh", age: 25, isDeveloper: true };
let jsonData = JSON.stringify(user);
console.log(jsonData); // Output: '{"name":"Ashutosh","age":25,"isDeveloper":true}'

Key JSON Rules & Best Practices

• Use double quotes ("") for keys and strings.
• Numbers and booleans should not be in quotation marks.
• Objects should use {} and arrays should use [].
• Values ​​can be nested objects or arrays.
• Use null for missing or unknown values.
• Always parse (JSON.parse()) or stringify (JSON.stringify()) when handling JSON in JavaScript

Thanks!

Also, Read: Explain the JavaScript AJAX Response