Android Development Android Performance Optimization

Question 1

Which tool in Android Studio provides a real-time graph of CPU, memory, network, and battery usage for a running app?

Accepted Answer

Android Profiler

Answer

Android Profiler provides real-time monitoring of CPU, memory, network, and energy usage directly within Android Studio.

Question 2

What is the primary cause of 'jank' (dropped frames) in Android applications?

Accepted Answer

UI thread work taking longer than 16ms per frame

Answer

Android targets 60fps, giving each frame 16ms; if the UI thread takes longer than that for a frame, the frame is dropped, causing jank.

Question 3

Which class should you use to run CPU-intensive work off the main thread while easily posting results back to the UI thread?

Accepted Answer

Coroutines with Dispatchers.IO

Answer

Kotlin Coroutines with Dispatchers.IO (for IO/CPU work) and Dispatchers.Main (for UI updates) is the modern, recommended approach for off-main-thread work.

Question 4

What does the term 'memory leak' mean in Android development?

Accepted Answer

An object is kept in memory longer than its intended lifecycle

Answer

A memory leak occurs when references prevent the garbage collector from reclaiming objects whose lifecycle has ended, such as an Activity referenced by a static field.

Question 5

Which Android tool helps detect memory leaks by watching for destroyed objects that are still referenced?

Accepted Answer

LeakCanary

Answer

LeakCanary is a popular open-source library that automatically detects memory leaks in Android apps by using weak references and heap dumps.

Android Development Practice Test

Android Development Practice Test

Android Development Android Performance Optimization