JSON

Purpose

To provide a language-neutral, human-readable, easy-to-parse data interchange format, replacing XML as the dominant Web API format.

Mechanism

It builds on two structures: collections of key-value pairs (objects {}) and ordered lists (arrays []). Values are strings (double quotes), numbers, booleans, null, objects, or arrays. The syntax is strict (double quotes, no trailing commas, no comments). RFC 8259 requires UTF-8 and forbids a BOM.

Use cases

• Web API requests and responses
• Configuration files (package.json, tsconfig)
• NoSQL document storage (MongoDB)
• Log and event data

Examples

• Input

  {"name":"Ada","age":36}

  Output

  The object {name:"Ada", age:36}

  Keys must be double-quoted

Common errors

Using single quotes or unquoted keys (invalid JSON)

Keys and string values must use double quotes