JavaScript Basics
A free “JavaScript Basics” deck containing 12 cards for local study.
constblock-scoped constant reference
letblock-scoped variable
functionfunction declaration
array.mapcreates a transformed array
array.filterkeeps matching elements
Promiserepresents a future result
async/awaitsyntax for asynchronous work
JSON.parseconverts JSON text into a value
addEventListenerregisters an event handler
localStoragesimple browser text storage
IndexedDBlocal browser database
Web Workerruns code outside the main thread