React Native Case Studies & Practical Application 4

Question 1

A video streaming app downloads HLS segments. Users on older Android devices report the player crashes. What is the most likely cause?

Accepted Answer

HLS is not supported on Android below API 26

Answer

Native HLS support on Android was added in API 26; older devices need an ExoPlayer-based library configured to handle HLS manually.

Question 2

A project management app allows drag-and-drop reordering of tasks. Which gesture handling approach is most suitable?

Accepted Answer

PanResponder tracking dy/dx and updating list order in onPanResponderRelease

Answer

PanResponder captures continuous drag gestures and provides the precise position data needed to update list order in real time.

Question 3

A survey app must work fully offline and sync answers when connectivity is restored. What is the recommended architecture?

Accepted Answer

Store answers in SQLite, detect connectivity with NetInfo, and sync when online

Answer

SQLite provides durable local storage while NetInfo allows detecting when the device comes back online to trigger a reliable sync.

Question 4

An analytics dashboard renders dozens of recharts-style SVG charts. The app feels sluggish on mid-range devices. What helps most?

Accepted Answer

Replace SVG charts with Canvas-based rendering via react-native-skia

Answer

react-native-skia renders graphics on the UI thread via its own Skia canvas, bypassing JS-thread bottlenecks that slow SVG-based charts.

Question 5

A real estate app shows property listings on a map with hundreds of markers. Performance degrades as markers increase. What is the solution?

Accepted Answer

Use marker clustering to group nearby pins and render aggregate counts

Answer

Marker clustering reduces the number of rendered map elements by grouping nearby markers, dramatically improving map performance.

React Native Practice Test