Overview
JSON Course
A structured introduction to JSON: syntax, types, parsing, generation, real-world patterns, and ecosystem tradeoffs.
This course teaches JSON as a data format—not how to click buttons in a particular app. JSON (JavaScript Object Notation) is the lingua franca of web APIs, configuration files, and structured logs.
Who this course is for
- Developers who see JSON every day but never learned the rules formally
- Students comparing JSON to JavaScript objects or other formats
- Anyone preparing to read API documentation or debug malformed payloads
What you will learn
- What JSON is and where it is used
- Syntax rules: brackets, commas, quotes, and colons
- The six value types JSON allows
- How objects and arrays nest to model real data
- Typical mistakes (trailing commas, comments, single quotes)
- JSON in REST APIs and configuration files
- String escaping and Unicode in JSON text
- JSON Schema for structure validation
- JSONPath for querying nested documents
- Parsing text into program values
- Generating JSON text from values
- Indentation, line breaks, and readable layout
- Inspecting JSON from files and logs
- List vs object document patterns
- JSON’s role and tradeoffs in modern systems
How to use this course
Use the table of contents on the left to move between lessons. Each lesson builds on the previous one. Read the overview first, then start with Lesson 1.
When you want hands-on practice after a lesson, the optional related tool can format and validate JSON—but understanding the format itself is the goal of this course.