Top 130 Android Interview Questions – Crack Technical Interview Now!

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Android Interview Questions and Answers from Beginner to Advanced level

DataFlair is committed to provide you all the resources to make you an android professional. We started with android tutorials along with practicals, then we published Real-time android projects along with source code. Now, we come up with frequently asked android interview questions, which will help you in showing expertise in your next interview.

android interview questions

Android Interview Questions – Get ready for your next interview

Android – one of the hottest technologies, which is having a bright future. Get ready to crack your next interview with the following android interview questions. These interview questions start with basic and cover deep concepts along with advanced topics.

Android Interview Questions for Freshers

1. What is Android?

Android is an open-source mobile operating system that is based on the modified versions of Linux kernel. Though it was mainly designed for smartphones, now it is being used for Tablets, Televisions, Smartwatches, and other Android wearables.

2. Who is the inventor of Android Technology?

The inventors of Android Technology are- Andry Rubin, Nick Sears, and Rich Miner.

3. What is the latest version of Android?

Technology is evolving rapidly!
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The latest version of Android is Android 10.0, known as Android Q. The upcoming major Android release is Android 11, which is the 18th version of Android. [Note: Keep checking the versions, it is as of June 2020.]

4. How many Android versions can you recall right now?

Till now, there are 17 versions of Android, which have their names in alphabetical order. The 18th version of Android is also going to come later this year. The versions of Android are here:

  • Android 1.0 – Its release is 23 September 2008.
  • Android 1.1 – Its release date is 9 February 2009.
  • Android 1.5 – Its name is Cupcake, Released on 27 April 2009.
  • Android 1.6 – Its name is Donut, Released on 15 September 2009.
  • Android 2.0 – Its name is Eclair, Released on 26 October 2009
  • Android 2.2 – Its name is Froyo, Released on 20 May 2010.
  • Android 2.3 – Its name is Gingerbread, Released on 06 December 2010.
  • Android 3.0 – Its name is Honeycomb, Released on 22 February 2011.
  • Android 4.0 – Its name is Ice Cream Sandwich, Released on 18 October 2011.
  • Android 4.1 – Its name is Jelly Bean, Released on 9 July 2012.
  • Android 4.4 – Its name is KitKat, Released on 31 October 2013.
  • Android 5.0 – Its name is Lollipop, Released on 12 November 2014.
  • Android 6.0 – Its name is Marshmallow, Released on 5 October 2015.
  • Android 7.0 – Its name is Nougat, Released on 22 August 2016.
  • Android 8.0 – Its name is Oreo, Released on 21 August 2017.
  • Android 9.0 – Its name is Pie, Released on 6 August 2018.
  • Android 10.0 – Its name is Android Q, Released on 3 September 2019.
  • Android 11.0 – As of now, it is Android 11.

5. Explain the Android Architecture with its components.

This is a popular android developer interview question

Android Architecture consists of 5 components that are-

a. Linux Kernel: It is the foundation of the Android Architecture that resides at the lowest level. It provides the level of abstraction for hardware devices and upper layer components. Linux Kernel also provides various important hardware drivers that act as software interfaces for hardwares like camera, bluetooth, etc.

b. Native Libraries: These are the libraries for Android that are written in C/C++. These libraries are useful to build many core services like ART and HAL. It provides support for core features.

c. Android Runtime: It is an Android Runtime Environment. Android Operating System uses it during the execution of the app. It performs the translation of the application bytecode into the native instructions. The runtime environment of the device then executes these native instructions.

d. Application Framework: Application Framework provides many java classes and interfaces for app development. And it also provides various high-level services. This complete Application framework makes use of Java.

e. Applications: This is the topmost layer of Android Architecture. It provides applications for the end-user, so they can use the android device and compute the tasks.

6. What are the services that the Application framework provides?

The Android application framework has the following key services-

a. Activity Manager: It uses testing and debugging methods.
b. Content provider: It provides the data from application to other layers.
c. Resource Manager: This provides users access to resources.
d. Notification Manager: This gives notification to the users regarding actions taking place in the background.
e. View System: It is the base class for widgets, and it is also responsible for event handling.

7. What are the important features of Linux Kernel?

The important features of the Linux Kernel are as follows:

a. Power Management: Linux Kernel does power management to enhance and improve the battery life of the device.
b. Memory Management: It is useful for the maximum utilization of the available memory of the device.
c. Device Management: It includes managing all the hardware device drivers. It maximizes the utilization of the available resources.
d. Security: It ensures that no application has any such permission that it affects any other application in order to maintain security.
e. Multi-tasking: Multi-tasking provides the users the ease of doing multiple tasks at the same time.

8. What are the building blocks of an Android Application?

This is a popular android interview question for freshers.

The main components of any Android application are- Activity, Services, Content Provider, and Broadcast Receiver. You can understand them as follows:

a. Activity- It is a class that acts as the entry point representing a single screen to the user. It is like a window to show the user interface.
b. Services- Services are the longest-running component that runs in the background.
c. Content Provider- The content provider is an essential component that allows apps to share data between themselves.
d. Broadcast receivers- Broadcast receiver is another most crucial application component. It helps the apps to receive and respond to broadcast messages from the system or some other application.

9. What are the important components of Android Application?

The Components of Android application are listed below:

  1. Widgets
  2. Intents
  3. Views
  4. Notification
  5. Fragments
  6. Layout XML files
  7. Resources

10. What are the widgets?

Widgets are the variations of Broadcast receivers. They are an important part of home screen customization. They often display some data and also allow users to perform actions on them. Mostly they display the app icon on the screen.

11. Can you name some types of widgets?

Mentioned below are the types of widgets-

a. Informative Widgets: These widgets show some important information. Like, the clock widget or a weather widget.
b. Collective Widgets: They are the collection of some types of elements. For example, a music widget that lets us change, skip, or forward the song.
c. Control Widgets: These widgets help us control the actions within the application through it. Like an email widget that helps check the recent mails.
d. Hybrid Widgets: Hybrid widgets are those that consist of at least two or more types of widgets.

12. What are Intents?

Intents are an important part of Android Applications. They enable communication between components of the same application as well as separate applications. The Intent signals the Android system about a certain event that has occurred.

13. Explain the types of intents briefly?

Intent is of three types that are-

a. Implicit Intents: Implicit intents are those in which there is no description of the component name but only the action.
b. Explicit Intents: In explicit intents, the target component is present by declaring the name of the component.
c. Pending Intents: These are those intents that act as a shield over the Intent objects. It covers the intent objects and grants permission to the external app components to access them.

14. What is a View?

A view is an important building block that helps in designing the user interface of the application. It can be a rectangular box or a circular shape, for example, Text View, Edit Text, Buttons, etc. Views occupy a certain area of the screen, and it is also responsible for event handling. A view is the superclass of all the graphical user interface components.

15. What do you understand by View Group?

It is the subclass of the ViewClass. It gives an invisible container to hold layouts or views. You can understand view groups as special views that are capable of holding other views, that are Child View.

16. What do you understand about Shared Preferences?

It is a simple mechanism for data storage in Android. In this, there is no need to create files, and using APIs, it stores the data in XML files. It stores the data in the pair of key-values. SharedPreferences class lets the user save the values and retrieve them when required. Using SharedPreferences we can save primitive data like- boolean, float, integer, string and long.

17. What is a Notification?

A notification is just like a message that shows up outside the Application UI to provide reminders to the users. They remind the user about a message received, or some other timely information from the app.

18. Give names of Notification types.

There are three types of notifications namely-

a. Toast Notification- This notification is the one that fades away sometime after it pops up.
b. Status Notification- This notification stays till the user takes some action on it.
c. Dialog Notification- This notification is the result of an Active Activity.

19. What are fragments?

A fragment is a part of the complete user interface. These are present in Activity, and an activity can have one or more fragments at the same time. We can reuse a fragment in multiple activities as well.

20. What are the types of fragments?

There are three types of fragments that are: Single Fragment, List Fragment, Fragment Transactions.

  1. Single Transactions can only show a single view for the user.
  2. List Fragments have a special list view feature that provides a list from which the user can select one.
  3. Fragment Transactions are helpful for the transition between one fragment to the other.

Frequently asked Android Interview Questions and Answers

21. What are Layout XML files?

Layout XML files contain the structure for the user interface of the application. The XML file also contains various different layouts and views, and they also specify various GUI components that are there in Activity or fragments.

22. What are Resources in Android Application?

The resources in Android Apps defines images, texts, strings, colors, etc. Everything in resources directory is referenced in the source code of the app so that we can use them.

23. Can you develop Android Apps with languages other than Java? If so, name some.

Yes, there are many languages that we can work with, for the development of Android Applications. To name some, I would say Java, Python, C, C++, Kotlin, C#, Corona/LUA.

24. What are the states of the Activity Lifecycle?

Activity lifecycle has the following four stages-

a. Running State: As soon as the activity starts, it is the first state.
b. Paused State: When some other activity starts without closing the previous one, the running activity turns into the Paused state.
c. Resume State: When the activity opens again after being in pause state, it comes into the Resume State.
d. Stopped State: When the user closes the application or stops using it, the activity goes to the Stopped state.

25. What are some methods of Activity?

The methods of Activity are as follows:

  • onCreate()
  • onStart()
  • onPause()
  • onRestart()
  • onResume()
  • onStop()
  • onDestroy()

26. How can you launch an activity in Android?

We launch an activity using Intents. For this we need to use intent as follows:

ntent intent_name= new Intent(this, Activity_name.class);
  startActivity(intent_name);

27. What is the service lifecycle?

There are two states of a service that are-

a. Started State: This is when the service starts its execution. A Services come in start state only through the startService() method.
b. Bounded State: A service is in the bounded state when it calls the method bindService().

28. What are some methods of Services?

The methods of service are as follows-

  • onStartCommand()
  • onBind()
  • onCreate()
  • onUnbind()
  • onDestroy()
  • onRebind()

29. What are the types of Broadcast?

Broadcasts are of two types that are-

a. Ordered Broadcast: Ordered broadcasts are Synchronous and work in a proper order. It decides the order by using the priority assigned to the broadcasts.
b. Normal Broadcast: These are asynchronous and unordered. They are more efficient as they run unorderly and all at once. But, they lack full utilization of the results.

30. What are useful impotent folders in Android?

The impotent folders in an Android application are-

  1. build.xml- It is responsible for the build of Android applications.
  2. bin/ – The bin folder works as a staging area to wrap the files packages into the APK.
  3. src/ – The src is a folder where all the source files of the project are present.
  4. res/ – The res is the resource folder that stores values of the resources that are used in the application. These resources can be colors, styles, strings, dimensions, etc.
  5. assets/ – It provides a facility to include files like text, XML, fonts, music, and video in the Android application.

31. What are the important files for Android Application when working on Android Studio?

This is an important android studio interview question

There are following three files that we need to work on for an application to work-

a. The AndroidManifest.xml file: It has all the information about the application.
b. The MainActivity.java file: It is the app file that actually gets converted to the dalvik executable and runs the application. It is written in java.
c. The Activity_main.xml file: It is the layout file that is available in the res/layout directory. It is another mostly used file while developing the application.

32. Which database do you use for Android Application development?

The database that we use for Android Applications is SQLite. It is because SQLite is lightweight and specially developed for Android Apps. SQLite works the same way as SQL using the same commands.

33. Tell us some features of Android OS.

The best features of Android include-

  1. Multi-tasking
  2. Support for a great range of languages
  3. Support for split-screen
  4. High connectivity with 5G support
  5. Motion Control

34. Why did you learn Android development?

Learning Android Studio is a good idea because of the following-

  1. It has a low application development cost.
  2. It is an open-source platform.
  3. It has multi-platform support as well as Multi-carrier support.
  4. It is open for customizations.
  5. Android is a largely used operating system throughout the world.

35. What are the different ways of storage supported in Android?

The various storage ways supported in Android are as follows:

  1. Shared Preference
  2. Internal Storage
  3. External Storage
  4. SQLite Databases
  5. Network Connection

36. What are layouts?

Layout is nothing but arrangements of elements on the device screen. These elements can be images, tests, videos, anything. They basically define the structure of the Android user interface to make it user friendly.

37. How many layout types are there?

The type of layouts used in Android Apps are as follows:

  1. Linear Layout
  2. Relative Layout
  3. Constraint Layout
  4. Table Layout
  5. Frame Layout
  6. Absolute Layout
  7. Scrollview layout

38. What is an APK?

An APK stands for Android Package that is a file format of Android Applications. Android OS uses this package for the distribution and installation of the Android Application.

39. What is an Android Manifest file?

The manifest file describes all the essential information about the project application for build tools, Android operating system, and google play. This file is a must for every Android project that we develop, and it is present in the root of the project source set.

40. Tell the tasks performed by AndroidManifest.xml file.

Manifest file is an essential part of any Android Project, and it does various things such as-

  • It provides a unique name to the Java package, and this name is a unique identifier for the application.
  • Manifest file describes many components of the application and the classes that implement them. These components include Activity, Services, Content Providers, Receivers, etc.
  • It also protects the application as all the permissions of the app are declared here.
  • Also, it declares the API that is useful for the Application.

41. What is an ADT, and what is its use?

ADT in Android is an abbreviation of Android Development Tools. It is a very powerful plugin used in Eclipse IDE. It specifically gives an integrated environment to develop Android Applications.

42. What is an ADB?

ADB stands for Android Debug Bridge. It is a versatile command-line tool that helps in enabling communication with a device. It facilitates users to perform a variety of actions on the device. These actions include installing and debugging the application, and access to UNIX shell that helps in running a variety of device actions.

43. What is ANR?

ANR is an abbreviation of Android not responding. It depicts an Error in a dialog box stating about unresponsive Android application. There are two conditions that causes ANR-

  1. If an active app doesn’t respond to an input event in 5 seconds.
  2. The broadcast receiver doesn’t finish executing even after a long time.

44. How to prevent ANR?

Android Not Responding (ANR) is an error, and there is only one way to prevent it that is by creating a child thread. This child thread will contain most of the code that actually works so that the main thread runs with minimal unresponsive time.

45. What is AAPT?

AAPT is an abbreviation of Android Packaging Tool. It provides the android app developers with the ability to deal with the zip-compatible archives. For that, it has the ability of creating, extracting, and viewing.

46. What is a Dialog box and tell its types.

A dialog box displays a dialog message with some actions. It interrupts and asks the users about their choice of action. It contains three parts that are- title, content, and action.

a. Alert Dialog- An alert dialog box supports 0-3 buttons and a list of elements. It is the most used Dialog box in Android.
b. Progress Dialog- This one displays the progress of some action or uploading or downloading. It is an extension of AlertDialog.
c. Date Picker Dialog- This one works for selecting dates by the user.
d. Time Picker Dialog- This one works for selecting time by the user.

47. What is a singleton class?

A singleton class is a class that has a very restricted instantiation. So, a singleton class can only have one instance at a time. It has its constructor as private, and it’s very useful to provide a global point of access to the object.

48. How does Android Track the application in process?

Android assigns a Unique ID to all the applications. This unique ID is called a Linux ID, and it helps in tracking the process of each application.

49. What is Gradle?

Gradle is an open-source build system that automates the building, testing, deployment, etc. It often uses the Java Virtual Machine supported languages like Java or Scala. It helps the developers by providing them flexibility while developing the application.

50. What are the operations provided by the Content Provider?

The operations performed by content providers are often referred to as CRUD operations. These operations are as follows-

  1. Create: It creates data for the content provider.
  2. Read: It reads the data that is present in the content provider.
  3. Update: It updates the data already existing in the content provider.
  4. Delete: It helps in deleting the data that is already there in the content provider.

51. What are the methods of content providers?

The methods of Content Provider are onCreate(), query(), insert(), update(), delete(), and getType().

52. What are URIs?

The URI stands for Uniform Resource Identifiers. These identifiers help in identifying the content providers. URI has two things that are Authority and the Path. Authority is the symbolic name of the provider, and Path points towards the data.

53. Name some User Interface components.

There are many things that come under the UI components. To name some, I would say Text View, Edit Text, Buttons, Image Button, Radio Button, Radio Group, Check Box, Spinner, Progress Bar, and many others.

54. What is event handling?

Event handling is nothing but managing the actions with the help of user’s interaction. These events can even collect user interaction’s data using interactive components. For example, clicking on a button makes it function when we use the onClick event handler.

55. What are the event Listeners?

An event listener is the interface of the View class of Android. It invokes a callback method when the user’s action activates the registered View.

56. What are the event handlers?

Event handlers are the methods that define the actions that will occur. Event handlers are invoked by the Event listeners once the user actions take place. These methods are useful as they help us to define some callback methods.

57. What is Event Listener Registration?

Event listener registration is nothing but registration of event listeners with event handlers. It is important because without registration, the Event handlers won’t be able to function.

58. What is the difference between a File, a Class, and an Activity?

A file is nothing but a block of resources for storing the information, whereas a class is a compiled form of .java file that Android uses to produce an exe apk. On the other hand, an activity is equivalent to a frame in the user interface. To load User Interface, components we need to extend this class.

59. What is a Toast? How to declare it?

A toast is a notification type that pops up on the user screen to give some message to the users. It appears on the screen only for some time and then disappears.
A toast can be declared as:

Toast.makeText(ProjectActivity.this, "..message...", Toast.LENGTH_LONG).show();

60. Can you deploy executable JARs on Android? Which package does it support?

No, in Android we cannot deploy executable JAR, the applications are packed into .apk format using AAPT and then deployed on Android platform.

61. What is the Sticky Intent?

A Sticky intent is a type of Broadcast that floats around even after the broadcast. They provide communication between a service and a function. Thus it allows others to collect data from it. This is a broadcast from the sendStickyBroadcast() method.

62. What are the commit() and apply() methods in Shared Preferences?

The commit() method returns a boolean value by writing the data synchronously. It returns 0 or 1.
The apply() method does not return any response, and it is Asynchronous.
Once you have used the apply() method and then if you call the commit() method, commit() won’t work until apply() finishes first.

63. What is the importance of having an Emulator?

An emulator lets the developer work on an application while checking it immediately. It also lets developers work well on the user interface. Emulators are very safe when it comes to testing the code while designing it.

64. What are containers in Android?

Containers, as per its name, hold objects and widgets together depending on the item it requires and their arrangements. Containers can hold labels, fields, buttons, etc.

65. What do you understand by Orientation?

Orientation describes the representation of the LinearLayout, whether it is row-wise or column-wise. The orientation can be set by using setOrientation() method. The values to set the orientation can be set only in two ways that are either Horizontal or Vertical.

66. What are the possible states for the process?

The four possible states in which a process can be are –

  1. Foreground Activity
  2. Visible Activity
  3. Background Activity
  4. Empty Process

Common Android Interview Questions

1. What do you understand about AIDL?

AIDL stands for Android Interface Definition Language. It handles the interface requirements between the client and the service to enable proper interprocess communication between them. It involves breaking the object into primitives so Android can understand it. We require this because one process can not access the memory of some other process.

2. Can we add fragments without using the user interface?

Yes, fragments can be added without using the user interface. We use the add(Fragment, string) method to add a fragment from the activity.

3. What is the main language used for Android Application development?

The main language for Android development is the Java Programming language. It is the most popular language for app development, as it is ideal for all Android developers. Not only this, but it is also announced as Google’s official language for Android Application development. And, we can develop any native Android applications, only using Java Programming Language.

4. What is an Android build tool?

The Android build tools is a set of programs that automates the creation of executable applications from its source code. The creation of these executable files includes compiling, testing, deployment, linking, and packing of the code into a usable form.

5. Name some exceptions in Android.

Some of the exceptions in Android are-

a. Inflate Exception: It comes when error conditions occur.
b. Surface.OutOfResourceException: It comes when the surface is not created/resized.
c. SurfaceHolder.BadSurface Type exception: It comes when “SURFACE_TYPE_PUSH_VUFFERS” is invoked.
d. WindowManaher.BadTokenException: It comes while trying to view an invalid WindowManager.LayoutParamstoken.

6. Which flags are used to run the application on Android?

There are the following two types of flags that we use to run the application:

  1. FLAG_ACTIVITY_NEW_TASK
  2. FLAG_ACTIVITY_CLEAR_TOP

7. What do you understand with the nine patch images tool?

With this tool, we can resize the images and change bitmap images into nine sections. These nine sections include four corners, four edges, and an axis.

8. What is an Adapter in Android?

An adapter is just like a bridge between the AdapterView and the data for it, respectively. It actually provides access to the data items by showing them in a view. An adapter implements the Adapter Interface and becomes the link to support data to be viewed in the AdapterView. The AdapterView is an object of a class extending the abstract AdapterView class. An Adapter helps the developers make the user interface interactive and user friendly.

9. What are the types of Android Adapters?

Six types of Adapter view are-

  1. BaseAdapter: It is the parent adapter.
  2. CursorAdapter: It makes binding of data values easier and more controlled.
  3. ArrayAdapter: It shows the items in a single list backed by an array.
  4. Custom ArrayAdapter: It helps in displaying the custom list of Array.
  5. SimpleAdapter: It helps in mapping static data to the views through XML.
  6. Custom SimpleAdapter: It displays customized lists and enables users to access the data.

10. What is an AdapterView?

An AdapterView displays the set of data in the form of List, Grid, or Spinner provided by the Adapter. AdapterView can display a large number of data items in the user interface and very efficiently. Android Adapter takes the data from its source and puts it in the AdapterView.

11. What are the types of AdapterViews provided by Android?

There are the following three types of AdapterViews provided by Android:

a. ListView: It shows the data in the form of a Horizontal list, and each item is placed right below the previous one.
b. GridView: It shows the data in a 2-Dimensional tabular form that is in Rows and Columns.
c. Spinner View: It is different from the previous two as in this, the users need to select one item from a list of items. This makes it more like a dropdown menu.

12. What is Google Android SDK?

The Google Android SDK is a software development kit. It is a toolset used by the Android developers to write the apps on Android devices. It also includes graphical interfaces, required libraries, emulators, relevant documents for Android APIs, and tutorials for the Android Operating System.

14. Tell the difference between Mobile testing and Mobile application testing.

The difference between mobile testing and Mobile application testing is that-

a. Mobile Testing is testing of the mobile device, and this test focuses on features of the device that includes Calling, SMS, Contacts, Camera, Media Players, Browsers, etc.
b. Mobile App Testing includes testing the working of the application, and it focuses on the functions and features of the application.

15. Tell the importance of setting permissions in Android?

The permissions in Android are set during the app development as with the help of these we can restrict the data and code only to the authorized users. If we write the codes without any restrictions, the chances for data or security to leak/breach would arise.

16. What is the .apk extension in Android?

APK stands for Application Package kit. The .apk extension is a default file format used by the Android Operating System. This is used for the installation of the application in any Android device as it contains resource files, certificates, manifest files, and other codes as well.

17. What do you mean by Activity Creator?

Activity creator was a batch file, and that is useful for creating new Android Project. Lately, Activity creator has been replaced by “Create New Project” in Android SDK.

18. Which tools can be used for debugging?

To find the reason why there is some bug or failure, we need debugging. In Android, AndroidMonitor.bat utility is a useful debugging tool and is used when required.

19. Can you name some mobile automation tools?

There are a considerable number of automation tools available in the market today, but these can only be useful if required or supported by the application. There are some paid tools like Silk Mobile, Ranorex, and See Test. To name some free tools, we can consider Appium, Robotium, and Calabash.

Android Development Interview Questions for Experienced professionals

1. How to troubleshoot the application crashing again and again?

To troubleshoot an application that is crashing continuously, we can do the following things:

a. Test the compatibility: Many times, it is possible that an application does not run in all the android devices due to lack of compatibility. So it is better to check their compatibility.
b. Proper Memory Management: Many times, it happens that an application can work on one device but not on the other. The reason for that is the processing power, memory management, and the CPU speed of the device. Thus for any app to run properly, the most important thing is Memory management in the device.
c. Free Up the memory space: In mobile devices, there is a limited space for apps to run. To avoid the app from crashing free up that memory space from the device.
d. Clear data usage: Another thing that could be done is clearing the data using application manager from settings. Clearing it will help and clear the cache memory and provide free space.

2. What is DDMS? What are the features of DDMS?

In Android Studio, we have a debugging tool that is DDMS. DDMS is an abbreviation of the Dalvik Debug Monitor Server. The features of Dalvik Debug Monitor Server are as follows-

  1. Port forwarding
  2. Capturing Screen on the device
  3. Information of Thread, Heap and also Radio State
  4. Logcat
  5. Location data spoofing
  6. Incoming calls and SMS spoofing

3. How to find memory leaks in Android applications?

In Android Studio, there is an Android Device Manager(ADM), which helps in detecting the memory leaks in the Android Platform. Upon opening it, there will be your device/ emulator with a heap sign on the left-hand side of the ADM. While running the app, you can see the heap size, memory analysis, etc. displayed on it.

4. Explain sensors in Android?

Android devices have some built-in sensors that measure the orientation, motion, and other conditions of the device. A sensor is a device/module or a subsystem that is useful to detect some events or actions. A sensor always works with some other electronic devices.
These sensors in Android devices provide data with high accuracy that helps to monitor the positioning and movement of the device. Some of these sensors are hardware-based, while some are software-based.

5. Name the types of sensors available for Android.

The sensors used in Android are of the following three types-

a. Motion Sensors: These are useful for rotational and acceleration forces, and it also includes gravity sensors, vector sensors, accelerometer, etc.
b. Environment Sensors: This is useful for measuring air temperature, pressure, humidity, etc.
c. Position sensors: They are useful for measuring the physical position of the device. It includes orientation sensors and magnetometers.

6. What are the classes for Sensors in Android?

The classes provided by Android to support these sensors are as follows-

  1. Sensor Manager class
  2. Sensor class
  3. SensorEvent class
  4. SensorEventListener class

7. Can a standard java bytecode run in Android?

Android makes use of Dalvik Virtual Machine that needs a special bytecode. First, the java class file is converted into a Dalvik executable file using an Android tool. Generally, the developers do not use this tool, build tools to take care of the generation of DVM compatible files.

8. Where and how do you define the icon for your activity.

We define this icon of the activity inside the manifest file of the application.
To declare it you can write:

<activity android:icon=”@drawable/app_icon” android:name=”.MyActivity”></activity>

Here drawable is a resource file that is present in the res/ folder. It will have an icon with the name app_icon.

9. How will your application perform actions that are provided by another application, like sending an email?

For this we have Intents. Intents contain an action to be performed, defined within them and they can launch the appropriate activity from another application. The syntax for this is:

Intent i= new Intent(Intent.ACTION_SEND);
i.putExtra(Intent.EXTRA_EMAIL, recipientArray);
startActivity(i);

10. How is data passed to the sub-activity?

To pass data to sub-activities we can use bundles. These bundles can transport information from an activity to the other. For this we can write the code as:

Bundle bundle=new Bundle();
  bundle.putString(“Email”, “[email protected]”);
  i.putExtras(bundle);

11. Why do you think open platforms are good for Mobile Operators?

An open platform helps speed up the development of applications and better customization options at a very lower cost. This will bring down the overall service cost as well as handset costs while boosting the sales of these handsets.

12. What are the differences between A Domain and a Workgroup?

A domain can have one or more computers as a server to manage the network. In this, the user doesn’t need an account to log in on a specific computer. Here computers can be on different networks.
On the other side, in a workgroup, all computers are peers and have no control over each other. Here the users need to have an account for each computer. Also, in the workgroup, all the computers must be in the same local network.

13. What is a Theme?

A theme is nothing but a set of properties that are bundled together in order to define a particular display setting. Android provides a few standard themes that are already listed in the resource file. The properties that include it are text size, color, background color, etc.

14. Are there any disadvantages in Android? Elaborate.

There are definitely some disadvantages of Android that are-

  1. There is no clear cut policy of how apps can adapt various OS versions.
  2. It can be challenging for developers to create apps that adjust every screen size properly.

15. Do all mobile phones support the latest Android operating system?

Some Android-powered phones allow users to upgrade to a higher Android version. However, not all the upgrades would allow users to get the latest version. It all depends on the capabilities and specifications of the Android device, and some devices might not be supporting them.

Android Interview Questions for Experienced

Apart from the questions listed above, below are some popular interview questions:

  • Explain your android project
  • Which is the biggest challenge you faced in the current project?
  • What are your roles and responsibilities?
  • How you convenience clients about the solution you provide?
  • Explain all the components and architecture of your project
  • Which are the best practices you follow while development of an android project?
  • Your first step before you start solving the problem?
  • How you debug the project and assure the quality

Open-ended Android Interview Questions

Along with the technical interview questions of android, you should prepare for the open-ended android interview questions:

  • Why should I hire you?
  • Why do you want to work for this company?
  • How you motivate yourself for continuous work?
  • Where do you see yourself in 10 years?
  • Why did you choose Java as a development language for your android project?
  • Tell me about your innovative solution which helped in project development?
  • Which forum do you use if you get any new issue or exception
  • How you modularize the project and assign work to the team?

Summary

In this tutorial, we have shown and guided you about how you can get ready and feel confident in your interviews. Also, we have given you a good number of android interview questions so you can practice them well. These android interview questions will help you strengthen your android development skills and provide support for your interviews. Thank You. All the best.

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