JSON

Overview

JSON (JavaScript Object Notation) is a lightweight, text-based data format introduced by Douglas Crockford in the early 2000s. It is derived from the object literal syntax of JavaScript but is language-independent. Today JSON is the most widely used format for data exchange between web clients and servers, configuration files, and APIs.

File Naming

Answer: kebab-case

user-data.json
api-config.json
database-schema.json

Why kebab-case?

• Cross-platform safe: No issues with case-insensitive file systems (Windows/macOS)
• Better readability in file lists and explorers
• URL-friendly: Works without encoding if files are served over HTTP

Key Naming

Answer: camelCase

{
  "userId": 123,
  "firstName": "Alice",
  "isActive": true
}

Why camelCase?

• Standard in the JavaScript/TypeScript ecosystem, where JSON originates
• The JSON specification itself does not prescribe a key style
• Most public web APIs (Google, GitHub, Stripe) use camelCase

Note

snake_case is common in Python-centric APIs (e.g. Django REST Framework, FastAPI). Pick one style and stay consistent within a project.

JSON vs. JSONC vs. JSON5

Feature	JSON	JSONC	JSON5
Comments	No	// and /* */	// and /* */
Trailing commas	No	Yes	Yes
Unquoted keys	No	No	Yes
Single-quoted strings	No	No	Yes
Typical use	Data exchange, APIs	Config files (VS Code, TypeScript)	Config files, human-edited data