Course · Advanced
Advanced JavaScript
Understand how JavaScript really runs: promises and the event loop, closures, modules and event delegation. Then use all of it to build a small app that talks to NEAR RPC, the same way near-api-js does under the hood.
0 of 5 lessons complete
What you will build
A NEAR account explorer that fetches live testnet data over JSON-RPC, with loading states, error handling, cancellation, and a cache.
Prerequisites
- The JavaScript foundations course: variables, functions, arrays, objects, and basic DOM.
Lessons
- 01Async/Await and Fetch in DepthPromises, async/await, error handling with fetch, running requests in parallel, timeouts and cancellation.2 min
- 02ES Modulesimport and export, named vs default exports, live bindings, dynamic import() for code splitting, and module scope.2 min
- 03DOM Events and UI PatternsCapture and bubble, event delegation, custom events, debounce and throttle, and rendering lists safely.3 min
- 04Closures and the Event LoopLexical scope and closures, private state, the classic loop bug, and how the call stack, microtasks and macrotasks decide execution order.2 min
- 05Mini App: NEAR Account ExplorerBuild a small app that reads live NEAR testnet data over JSON-RPC: state, validation, loading and error UI, caching, and race-condition handling.5 min