Top 50 Android Interview Questions and Answers 2020 May

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I am going to share basic Android Interview Questions with Answers. It's really helpful for Android fresher and Android experienced candidate for getting the right Android job.

Top 50 Android Interview Questions and Answers 2020 May


Define Explicit Intents

The intents that invoke the Activity are called Explicit Intents.

Define Handlers in Android

To manage threads, handlers are used. Handlers permits the communication between main thread and background thread. Users prefer handlers when there is a need to perform background task frequently for a given intervals in minutes.

Define Implicit Intents

The intents that calls the system components are called Implicit Intents.

Describe ActivityCreator

ActivityCreator is a shell script and batch file, helpful for creating a new project in Android. In Android SDK, ActivityCreator is replaced by “Create New Project”.

Describe Intent of Android

When there is a need for a user to navigate from one activity to the other one, Android is holding the Intent class. Intent is the one that displays notification to the users from the device and if required, users can act on that notification.

Describe services in Android

An android component that runs in the background and acting autonomously without providing any user interface are called services. As the services is recognised to run in the background, users can easily access any apps and continue to perform their own work.

Explain Android

Android is very famous for Tablets and smartphones and this is an open-source operating system. The operating system of Android is Linux Kernel. The developers are developing the programs or functions with the help of Android operating system to perform both advanced and basic operations on Smartphones.

Explain Android SDK

Android SDK is an efficient set of tools to write an app or develop a mobile application. This tool has a Graphical User Interface emulating an android environment. This kind of an emulator stands out to be an actual mobile where the developers can write the code and test the written the code.

Explain Orientation

Orientation which is available in smartphones these days provides the ability for screen rotation. Users can rotate the screen between vertical or horizontal mode.

Explain sleep mode process in Android

If sleep mode is ON, CPU is made to sleep and no commands are accepted from android devices, excluding alarm and radio interface layer.

Give the abbreviation for AIDL

AIDL – Android Interface Definition Language. This is used to simplify the communication between service and the client. Also, the inter-process communication can be used to pass the information.

Give the abbreviation of ANR

ANR – Application Not Responding. The Android platform displays a pop-up when too many functions are performed by the application at a time and at times, users will not receive any response from the system. Such kind of a pop-up notification is called ANR.

How many types of orientations are available in Android?

There are two (2) types of Orientations are available in Android, namely Portrait and Landscape.

If there is a leak in memory, how will you find it in an Android mobile app?

Android Device Manager is used to detect the memory leakage on all Android mobile apps.

If you start a new project in Android, what are the required components?

The components essential to start a new project in Android are build/, res/, manifest, assets/ and src/.

In Android, what are the flag types used to run an application?

FLAG_ACTIVITY_CLEAR_TOP and FLAG_ACTIVITY_NEW_TASK are the two types of flags.

In Android, which kernel is used?

Customised Linux 3.6 Kernel is used in Android.

Is it possible to debug on both emulators and real devices with the help of DDMS?

Yes, it is possible to debug on both emulators and real devices with the help of DDMS.

List out the Android vital core components

Services, Fragment, Activity, Content Provider and Intents are the core components of Android.

List out the data types which are supported by AIDL

Map, String, Data types of Java, charSequence, and List are the data types supported by AIDL.

List out the dialog boxes supported by Android

TimePickerDialog, AlertDialog, DatePickerDialog, and ProgressDialog are the dialog boxes supported by Android platform.

List out the different Android version along with its name.

Android 4.0 to 4.0.4 – Ice Cream Sandwich, Android 4.1 to 4.3 – Jelly Bean, Android 4.4 to 4.4.4 – Kitkat, Android 5 to 5.1.1 – Lollipop, Android 6 to 6.0.1 – Marshmallow, Android 7.0 to 7.1.2 – Nougat, and Android 8.0 – Oreo are the different android version and its names.

List out the various data storage options available on Android

Internal Storage, SharedPreference, External Storage and SQLite are the different storage options.

Mention the database which is used for android platform

Android platform make use of SQLite database, which is a serverless and open-source database.

Mention the tool names that is used for debugging in Android

Few tool names used for debugging in Android are given below:

  • Android Debug Bridge
  • iOS simulator
  • Android DDMS
  • Remote Debugging
  • Eclipse with ADT

Provide few details on how to troubleshoot android apps when the users faces the crashing regularly.

Users must free up the memory space and then must clear the usage of app data. Try to manage the memory often and perform compatibility testing using different mobile devices.

Provide few exceptions available in Android

SurfaceHolder.BadSurfaceTypeException, Inflate Exception, WindowManager.BadTokenException and Surface.OutOfResourceException are the exceptions available in Android.

Provide the Java classes available with respect to the Android sensors.

SensorEvent, Sensor Manager, SensorEventListener and Sensor are the Javaclasses available with respect to the Android sensors.

Provide the three CPU architectures of Android

ARMv7, ARMx86, and ARM64 are the three (3) CPU architectures of Android.

Provide the types of Intents

Implicit and Explicit Intents are the two (2) types of Intents available in Android.

What are sensors?

To measure motion, orientation and few other conditions of an android devices, we do have a feature called built-in sensors.

What are the different states of Activity Lifecycle in Android?

The different states of Activity Lifecycle in Android are given below:

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

What are the Launch modes available in Android?

SingleTop, SingleInstance, Standars and SingleTask are the four (4) Launch modes available in Android.

What are the layers in the Android architecture?

Linux Kernel, Hardware Abstraction Layer, Android Runtime, Application Framework and Applications are the layers in the Android Architecture.

What are the mobile automation testing tools in market?

Robotium, Appium, Calabash, and KIF are the free automation tool. SeeTest, Silk Mobile and Ranorex are the paid tools.

What are the sensor categories available in Android devices?

Position Sensors, Motion Sensors and Environmental Sensors are the three categories of sensors available in Android devices.

What are the services available in Android?

Bound Services, Background Services and Foreground Services are the three (3) services available in Android.

What is AndroidManifest.xml file in Android?

Before running an app code, every android system should ensure to have AndroidManifest.xml file in the root directory. This file contains information on Android components like Content Providers, Activity, Broadcast Receivers, Services, etc and the package name.

What is the abbreviation of ADB?

ADB stands for Android Debug Bridge, a command line tool performing shell commands. To enable the communication directly between the emulator parts, ADB is used.

What is the abbreviation of ADT?

ADT – Android Development Tool, which is useful in developing and testing the applications.

What is the abbreviation of APK?

APK stands for Android Packaging Key.

What is the abbreviation of DDMS?

DDMS stands for Dalvik Debug Monitor Server, which is a debugging tool used by Android Studio.

What is the abbreviation of NDK?

NDK – Native Development Kit.

What is the method used to set the orientation?

The method used to set the orientation is ‘setOrientation’ and this can easily set the screen configurations.

What is the method used while changing the orientation from one to the other?

The method ‘onCreate()’ is used while changing the orientation from vertical to horizontal or vice-versa.

What is the reason for not running bytecode in Android?

Rather using Java Virtual Machine (JVM), Dalvik Virtual Machine is used by Android. Hence, it is not possible to run bytecode in Android.

What is the use of NDK?

If you want to use the native language like C or C++ to develop a part of an app, NDK is very much helpful.

What is the use of permission setup in app development?

Only the authorized users are permitted to use the code and data once the permission setup is completed in app development.

What is the use of Thread?

If there are long running operations from main thread, Thread is used to separate those to improve the performance.

Which language is supporting Android development?

Android development widely uses the language Java. In addition, it supports C or C++ when using Android SDK. This really enhances the performance speed.

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