JavaScript Object Notation (JSON)

What is JavaScript Object Notation (JSON)?

JavaScript Object Notation (JSON) is a lightweight data-interchange format that is used for transmitting data over the internet. It is based on a subset of the JavaScript programming language and is easy for humans to read and write. JSON is primarily used to transmit data between a server and a web application, as an alternative to XML.

In JSON, data is represented as a collection of key-value pairs, with each key being a string and each value being either a string, a number, a boolean value (true or false), an array, or an object. Arrays and objects can contain other arrays and objects, allowing for the creation of complex data structures.

Here is an example of a simple JSON object:


 "name": "John Smith",
 "age": 30,
 "isEmployed": true,
 "skills": ["JavaScript", "HTML", "CSS"]


In this example, the object has four properties: "name", "age", "isEmployed", and "skills". The value of the "name" property is a string, the value of the "age" property is a number, the value of the "isEmployed" property is a boolean, and the value of the "skills" property is an array of strings.

JSON is widely used in web development as a way to send and receive data between a server and a client. It is often used in conjunction with AJAX (Asynchronous JavaScript and XML) to update parts of a web page without needing to reload the entire page. JSON is also used in many other contexts, such as storing data in databases and as a configuration format for software applications.

See Also