NativeScript for Mobile App Development Performance and Debugging 2

Question 1

What causes UI jank in NativeScript applications?

Accepted Answer

Running heavy computations synchronously on the main (UI) thread

Answer

Using too many plugins

Answer

Having too many routes defined

Answer

Using TypeScript instead of JavaScript

Question 2

Which NativeScript API runs code in a background thread?

Accepted Answer

Worker API (new Worker())

Answer

setTimeout with 0ms delay

Answer

setImmediate()

Answer

async/await

Question 3

What is the purpose of tree shaking in a NativeScript webpack build?

Accepted Answer

Remove unused JavaScript code from the bundle to reduce app size

Answer

Optimize image assets

Answer

Remove unused CSS rules

Answer

Prune unused native dependencies

Question 4

Which NativeScript ListView optimization recycles view cells to improve scroll performance?

Accepted Answer

Cell/view recycling via the itemTemplates and key template mechanism

Answer

Lazy data loading only

Answer

Virtual DOM diffing

Answer

GPU-accelerated rendering

Question 5

What does the `--clean` flag do when running `ns build`?

Accepted Answer

Deletes the platforms folder and rebuilds native projects from scratch

Answer

Clears the webpack cache only

Answer

Removes node_modules

Answer

Resets the app's local storage

Question 6

Which profiling tool measures rendering performance of NativeScript iOS apps?

Accepted Answer

Xcode Instruments (Time Profiler)

Answer

Chrome DevTools Performance tab

Answer

Android Studio CPU Profiler

Answer

ns profile ios