What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that's easy for humans to read and write, and easy for machines to parse and generate.

Understanding JSON

JSON has become the de facto standard for data exchange on the web. It was originally derived from JavaScript, but it's now a language-independent format supported by virtually every modern programming language.

JSON Syntax

JSON data is written as key-value pairs, similar to JavaScript object literals. Here's a simple example:

{
  "name": "John Doe",
  "age": 30,
  "email": "john@example.com",
  "isActive": true
}

Data Types in JSON

JSON supports the following data types:

• String: Text enclosed in double quotes - "Hello World"
• Number: Integer or floating-point - 42 or 3.14
• Boolean: True or false values - true or false
• Array: Ordered list of values - ["apple", "banana", "orange"]
• Object: Collection of key-value pairs - {"key": "value"}
• Null: Empty value - null

Why Use JSON?

Common Use Cases

• API Responses: RESTful APIs commonly return data in JSON format
• Configuration Files: Many applications use JSON for configuration
• Data Storage: NoSQL databases like MongoDB store data as JSON documents
• Web Applications: AJAX requests typically exchange JSON data

JSON vs XML

While XML was once the standard for data exchange, JSON has largely replaced it due to:

• Simpler syntax with less verbosity
• Faster parsing and smaller file sizes
• Native JavaScript support
• Better readability

Working with JSON

Most programming languages provide built-in functions to parse JSON strings into native objects and serialize objects back into JSON strings. For example, in JavaScript:

// Parse JSON string to object
const obj = JSON.parse('{"name":"John","age":30}');

// Convert object to JSON string
const jsonString = JSON.stringify({name: "John", age: 30});