Android Interview Questions Collections — P1

Today I will share the basic knowledge that employers refer to using interviews (The answers and new question will be updated constantly and hope to get your contributions in the comment section):

Core Android

• How does the Android notification system work?
• How can two distinct Android apps interact? (several answers)
• Describe Activities. [info]
• What are the four states of the Activity Lifecycle? [active/running, paused, stopped, destroyed]
• What are the seven callback methods of an Activity used to perform operations when the Activity transitions between states? [onCreate(), onStart(), onResume(), onPause(), onStop(), onRestart(), onDestroy()]
• What is the difference between a fragment and an activity? Explain the relationship between the two.
• What is the difference between Serializable and Parcelable? Which is the best approach in Android?
• What are “launch modes”?
• What are Intents? [info]
• What is an Implicit Intent? [info]
• What is an Explicit Intent? [info]
• Describe three common use cases for using an Intent.
• What is a Service? [info]
• What is a ContentProvider and what is it typically used for? [info]
• What is a Fragment? [info]
• What is ADB?
• What is ANR?
• What is AndroidManifest.xml used for? Give examples of what kind of data you would add to it. [info]
• Describe how broadcasts and intents work to be able to pass messages around your app.[info]
• What is the Dalvik Virtual Machine?
• What are different ways to store data in your Android app? [info]
• Android appplication components [info]
• What is the relationship between the life cycle of an AsyncTask and an Activity? What problems can this result in? How can these problems be avoided?
• What is the difference between Service and IntentService? How is each used?
• What is a Sticky Intent?
• What is AIDL? [info]
• What is dependency injection?
• What are the different protection levels in permission? [info]
• How would you preserve Activity state during a screen rotation?
• Relative Layout vs Linear Layout.
• How to implement XML namespaces?
• Difference between View.GONE and View.INVISIBLE?
• What is the difference between a regular bitmap and a nine-patch image?
• Tell about the bitmap pool. Mindorks
• How to avoid memory leaks in Android? Mindorks
• What are widgets on Home-Screen in Android?
• What is AAPT?
• How do you find memory leaks in Android applications? Mindorks
• How do you troubleshoot a crashing application?
• Why should you avoid to run non-ui code on the main thread?
• How did you support different types of resolutions?
• What is Doze? What about App Standby?
• What can you use for background processing in Android?
• What is ORM? How does it work?
• What is a Loader?
• What is the NDK and why is it useful?
• What is the StrictMode?
• What is Lint? What is it used for?
• What is a SurfaceView?
• What is the difference between ListView and RecyclerView?
• What is the ViewHolder pattern? Why should we use it?
• What is a PendingIntent?
• Can you manually call the Garbage collector?
• What is the best way to update the screen periodically?
• What are the different types of Broadcasts?
• Have you developed widgets? Describe. Mindorks
• What is Context? How is it used? Medium
• Do you know what is the view tree? How can you optimize its depth?
• What is the onTrimMemory method?
• Is it possible to run an Android app in multiple processes? How?
• How does the OutOfMemory happens?
• What is a spannable?
• What is overdraw? Developer Android
• What is renderscript? Mindorks
• What are the differences between Dalvik and ART?
• FlatBuffers vs JSON. Mindorks
• What are Annotations? Mindorks, Link
• Tell about Constraint Layout Mindorks
• HashMap, ArrayMap and SparseArray Mindorks
• Explain Looper, Handler and HandlerThread. Mindorks
• How to reduce battery usage in an android application? Mindorks
• What is SnapHelper? Mindorks
• How to handle multi-touch in android GitHub
• What is the difference between a regular .png and a nine-patch image?

Android Design and XML

• Explain the differences and similarities of Relative Layout and Linear Layout.
• Explain the differences and similarities of List Views and Grid Views.
• Describe how to implement XML namespaces.
• Explain how to present different styles/drawables for a button depending on the state of the button (pressed, selected, etc.) using XML (no Java) [info]
• for layout_width and layout_height, what’s the difference between match_parent and wrap_content?
• How do you implement Google’s new Material Design in an Android application? [info]
• Difference between View.GONE and View.INVISIBLE?

Android Networking

• Have you use an HTTP Library, which, why, did you like it?
• Describe how REST APIs work.
• What are some typical methods of HTTP request/responses? [GET, POST, PUT, PATCH, DELETE, UPDATE]

Databases

• Why does Android use SQLite?
• What libraries have you used for interacting with databases and why did you choose them?
• What are contract classes? [info]
• How do you use the BaseColumns interface to describe your data schema? [info]

Android Test Driven Development

• What is Espresso? Developer Android
• What is Robolectric? Robolectric
• What is UI-Automator? Developer Android
• Explain unit test.
• Explain instrumented test.
• Have you done unit testing or automatic testing?
• Why Mockito is used? Official site
• Describe JUnit test.

I hope it is a source for you to reinforce your knowledge before the interview. Looking forward to your further contributions and questions. Thank you!

Reference :
— Mindorks blog
— Github

Originally published at Code for fun.