Reference
Reference pages are useful on their own — a one-sentence purpose, a minimal example, syntax, edge cases, and runtime notes — and link back to the lessons that teach the concept in context.
Categories
Syntax
Declarations, operators, statements, and language forms.
Built-ins
Standard objects, methods, and global functions.
Browser
Web APIs: the DOM, events, storage, and fetch.
Node.js
Node-specific APIs and runtime behavior.
Patterns
Recurring designs and idioms.
Errors
Built-in error types and what triggers them.