JSON Concepts & Fundamentals

What JSON is, its data types, and how it works across JavaScript, Python, and Node.js.

·8 min read

app.json / app.config.js Explained: Configuring an Expo / React Native App

Expo's app.json controls your app's name, icon, splash screen, permissions, and native build settings — all from one JSON file. Every key that matters, and when you need app.config.js instead.

·8 min read

JSON Import Attributes: import data from './x.json' with { type: 'json' }

ES2025 standardized importing JSON modules with the `with { type: 'json' }` syntax. How it works, why the type attribute is required, dynamic imports, and the security reason behind it.

·7 min read

How to Convert JSON to an Array in JavaScript

Turn JSON into a JavaScript array — parse a JSON array, convert a JSON object to an array with Object.keys, values and entries, extract field values, and export to CSV.

·9 min read

JSON Interview Questions — A 2026 Guide for Developers

The JSON questions that actually come up in technical interviews — data types, parsing pitfalls, and system-design tradeoffs — with code examples, not just definitions.

·9 min read

Working with JSON in Rust: A serde_json Guide

Handle JSON in Rust with serde: derive Serialize/Deserialize for typed structs or use serde_json::Value, plus renaming, optional fields, and defaults.

·9 min read

Dates in JSON: ISO 8601, Timestamps & Timezone Pitfalls

JSON has no date type. Learn the right way to represent dates and times in JSON — ISO 8601, Unix timestamps — and how to avoid the classic timezone bugs.

·7 min read

Big Numbers in JSON — Why Large IDs Silently Break in JavaScript

JSON.parse turns every number into a 64-bit float, which quietly loses precision above 2^53. Here's exactly where that bites — 64-bit database IDs, Snowflake IDs — and how every major API works around it.

·10 min read

GeoJSON Explained: The JSON Format Behind Every Map

How GeoJSON represents points, lines and polygons as plain JSON — the format behind Google Maps exports, Mapbox, Leaflet, PostGIS and every geospatial API you'll touch.

·9 min read

Structuring i18n Translation JSON Files the Right Way

How react-i18next, next-intl and Flutter's ARB files structure translation JSON — nesting, pluralization, interpolation and the pitfalls that break at 20+ languages.

·8 min read

null vs undefined in JSON: Handle Missing Values Right

null vs undefined in JSON, explained simply. See why JSON.stringify drops undefined, how to safely read missing values, and the best practice for clean API responses.

·9 min read

JSON in JavaScript: parse, stringify, fetch and localStorage

Complete guide to working with JSON in JavaScript: JSON.parse, JSON.stringify, fetch API, localStorage, deep cloning, and handling dates. With examples.

·8 min read

What is JSON? A Complete Beginner's Guide

Learn what JSON is, how it works, and why it is the most popular data format for APIs and web applications in 2025.