Everything in Frontend Dev
Template syntax vs JSX: framework design trade-offs?
Templates (Vue, Angular) are declarative, easier to learn, enable static analysis; JSX (React, Solid) is code-based, flexible, familiar to JavaScript developers.
Server-side data fetching in Nuxt 3?
Use useFetch or useAsyncData to fetch on server, data is serialized and injected into page state, component accesses it as reactive data.
AOT vs JIT compilation: what does ahead-of-time win?
AOT compiles templates at build time (catches errors early, smaller bundle, faster startup), JIT compiles in browser (slower startup, larger bundle, flexible).
Hydration: SSR HTML to interactive app?
Server renders HTML, client JavaScript bootstraps and attaches event listeners (hydration), mismatch occurs if server HTML differs from client render.
Testing shared Vue components: unit, a11y, visuals?
Unit tests (Vitest/Jest) for logic, accessibility tests (axe, Pa11y) for ARIA/keyboard, visual regression (Percy, Chromatic) for rendering.
Zone.js and change detection optimization in Angular?
Zone.js wraps async (timers, events, HTTP), triggering change detection after each; use runOutsideAngular when external libraries fire high-frequency events.
When to adopt Pinia or NgRx over simple services?
Services work for small apps; use Pinia/NgRx when state is shared across many components, mutations are complex, or debugging/undo matters.
Compiler vs runtime reactivity: Svelte, Vue, Angular?
Svelte compiles away reactivity (smaller bundles, zero-cost), Vue/Angular use runtime Proxies/zone.js (flexible but heavier).
Compile-time vs runtime prop validation across frameworks?
TypeScript (compile-time) catches errors before build; Vue props validation (runtime) catches at runtime; tradeoff: TS is stricter, Vue validation is flexible but less safe.
Content projection: slots vs props for composition?
Slots let parent pass markup (not data) to child, child renders it as-is, vs props pass values; slots excel when parent needs full layout control.
Prerendering vs SSR in SvelteKit: trade-offs?
Prerender generates static HTML at build, SSR renders on each request, prerender wins on speed but requires static data.
What isolatedModules enforces and why bundlers need it
IsolatedModules forbids features needing cross-file type info because Babel and esbuild compile each file alone; const enums, certain re-exports, and namespace tricks are flagged.
First compilerOptions to set after tsc --init
Enable strict for full type safety, set target and module to match the runtime, and choose outDir/rootDir or moduleResolution; each tightens checks or aligns output.
WebRTC signaling: SDP, ICE, and the signaling server
Peers exchange SDP offer and answer describing media via an out-of-band signaling server, then trade ICE candidates to find a network path using STUN and TURN.
Dedicated vs Shared vs Service Workers compared
Dedicated worker serves one page for offloading CPU; Shared worker is one instance across same-origin contexts via ports; Service worker is a network proxy for caching and push, event-driven and killable.
Generic merge with an intersection return type
Use two type parameters T and U, return T & U, spread both objects; note later spread wins on key collisions and the type may not reflect that.
Promise .catch() versus async/await try...catch
.catch() handles rejection for all preceding chain steps and reads functionally; try/catch reads synchronously and can scope errors per await, but only catches awaited rejections.
Implementing the Singleton pattern in TypeScript
Private constructor blocks new, a static private instance field caches it, static getInstance lazily creates and returns the one instance.
Understanding this in TypeScript
In TypeScript, this is determined by how a function is called, not where it is defined; arrow functions capture the enclosing this lexically, and TypeScript adds optional this parameters to type-check the expected context at compile time.
Purpose of Outlet in React Router v6 nested routes
Outlet renders the matched child route inside a parent layout, enabling shared chrome with swappable content; configure nested routes and place Outlet where children render.
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