Top 31 Android Developer Interview Questions and Answers for 2024

Android Interview Questions

1: For starters, what’s Android anyway? 

Android is a Linux-based, open-sourced operating system commonly found on mobile devices, such as smartphones and tablets. It’s a kernel-based system that gives developers the flexibility to design and deploy simple and/or advanced apps.

2: What is the current version of Android, and how old is it?

The current version of Android is 9.0, also called Android Pie, and it came out in August of 2018.

3: What database is used for the Android platform?

SQLite, an open-source, self-contained, serverless database, is embedded in Android by default.

4: What is an android application architecture?

The Android architecture consists of:

• Android Framework
• Android Applications
• Linux Kernel
• Libraries

5: Can you change an application’s name after you have deployed it?

Although you CAN change it, the real question should be “SHOULD you”? Changing an application’s name risks breaking some of its functionality.

6: Name the basic tools for developing an Android App

The tools used for development are:

• JDK
• SDK Tools
• Eclipse+ADT Plugin

7: List of Android’s advantages.

The four main advantages of Linux are:

• Open source, so it’s free
• It’s platform-independent, so it supports Windows, Linux, and Mac
• It supports a number of different technologies, such as Bluetooth, speech, cameras, Wi-Fi, etc.
• It employs DVM (Dalvik Virtual Machine), a highly optimized virtual machine

8: Explain the Android SDK.

This is a set of tools that Android developers use in order to develop or write apps. It features a graphical user interface that emulates a handheld, Android-driven environment, making it easier for developers to create, test, and debug their code.

The tools include:

• Dalvik Debug Monitoring Services
• Android Emulator
• Android Asset Packaging Tool
• Android Debug Bridge

9: Speaking of emulators, why is it so important for developers to have access to one?

Since emulators function like an actual hand-held device, developers have a good dedicated “sandbox” to safely create, edit, test, and debug new applications, seeing how they would function on a real device without having to actually risk a real device.

10: What languages does Android use?

Android-primarily uses Java, but it also supports C/C++, which, if used with Android SDK, will run faster.

11: What’s an android framework?

It’s a set of APIs that permits developers to create apps, and consists of:

• Intent
• Activities
• Content Providers
• Others

12: What’s an intent in the context of Android? Describe the different types.

Much what it sounds like, it’s the intention to perform an action, a message that is passed between components. Intents request actions from a different component, such as sending an email, opening a web page, or launch a given activity. The two types are:

• Implicit Intent

  This is where the intent doesn’t define the target component, requiring the Android system to conduct an evaluation of the components.

• Explicit Intent

  On the other hand, the explicit intent directly identifies the target component.

13: What’s a sticky intent?

This is a broadcast using the send sticky broadcast() method. The intent sticks around after the broadcast, which allows others to collect data from it.

14: What are Activities?

These are the parts of a mobile app that a user sees and interacts with. It represents a Graphic User Interface (GUI), representing one Android screen.

15: What are the four essential activity states?

The four states are:

• Active: The activity is at the top of  the stack, running in the foreground
• Paused: The activity is still visible but cannot receive user input events; it’s in the background
• Stopped: The activity is invisible and consequently is paused, and obscured or hidden by a different activity
• Destroyed: The activity’s process has been killed, completed, or terminated

16: What’s a content provider?

Content providers share information between different Android applications. They allow users to access data within an application. Examples include contact information, images, video, and audio.

17: Explain Android Toast.

Toast, in this case, is a pop-up box (hence the word) giving feedback regarding an operation that the users initiated, informing the user of the current status of said operation. For instance, when a smartphone user sends a message to a friend, a toast is displayed saying “sending message”.

18: What’s the difference between mobile testing and mobile application testing?

Mobile Testing is performed on the mobile device itself, specifically on the device’s features like Contacts, SMS, the browsers, and it’s Calling function. Mobile Application Testing tests the features and functions of the apps loaded onto a mobile device.

19: What’s a “bundle” in Android?

Bundles are used to pass the required data to sub-folders.

20: How do you identify view elements in an android program?

Use the keyword findViewById.

21: Does Android have any drawbacks?

Android’s weaknesses stem from one of its advantages, namely that it’s everywhere and can run on a huge number of devices.

• First of all, developers can encounter difficulty in creating apps that easily adjust the display to accommodate the widely disparate screen sizes of all these different devices.
• Secondly, the large number of devices has given rise to a large number of custom-made Android versions to suit them, thus there is no central set of policies governing upgrades, or parameters for running on many operating systems. It’s anarchy out there!

22: Can Bytecode that is written in Java run on Android?

No, it cannot.

23: What is AAPT?

This is an acronym for Android Asset Packaging Tool. The tool gives developers the ability to deal with zip-compatible archives, including content viewing, creation, and extraction.

24: What is ADB?

This acronym stands for Android Debug Bridge (a tool found in SDK). It’s a command-line tool used to communicate between the emulator instances.

25: What does APK mean?

It’s short for Android Packaging Kit. Every file in the Android packaging key is compressed into a single file, the APK.

26: Explain ANR.

This is an acronym for Application Not Responding, a pop-up or notification that kicks in when the application is experiencing lag time for the user due to too many functions being performed simultaneously.

27: How do you place layouts in Android? Where are they placed?

They’re placed as XML files, in the layout folder.

28: Give some examples of Android exceptions. 

Exceptions include:

• Inflate Exception
• Surface.OutOfResourceException
• SurfaceHolder.BadSurfaceTypeException
• WindowManager.BadTokenException

29: What are the four essential items in every Android project?

The four essential items are:

• AndroidManifest.xml
• build.xml
• bin/
• src/
• res/
• assets/

30: List the four Android supported dialogue boxes.

The four dialogue boxes are:

• Alert Dialog: Features selectable elements such as radio buttons and/or checkboxes
• Progress Dialog: Shows progress, either via a progress wheel or bar
• Date Picker Dialog: Lets the user select a date
• Time picker Dialog: Lets the user select a time

31: An Android application keeps crashing. How do you resolve the issue?

When an application crashes often, these are the best ways to fix it -

1. It could be a memory space issue. Make sure there’s enough memory space.
2. Clear the app data by clearing the cache memory using “settings” under Application Manager.
3. Not all apps run the same on assorted machines, so you may have to tinker with memory management.
4. It may be a matter of compatibility; a problem that can be headed off by testing the app on as many of your devices as possible beforehand.

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