Basic Android interview questions for freshers and experienced developers and testers:
In this technological era, there is a huge demand for Android Application developers and it is one of the highly paid jobs too.
Hence many tech-savvy people are trying to make their way into this career. There are several tricky interview questions that are asked in many MNC’s and some small scale companies. And this article includes a set of such Android interview questions and answers that will be helpful to millions of job seekers.
Let’s Explore!!
This article includes a set of most commonly asked android interview questions and answers covering almost all the important concepts in simple terms in order to enable any job seeker to clear the interview successfully.
Most Popular Android Interview Questions & Answers
Given below is the list of most commonly asked Android Interview questions
Q 1) What is Android?
Answer: Android is an open-source operating system and is mainly popular for Smartphones and Tablets.
This operating system is Linux Kernel-based. Using the Android operating system, the developer develops the functions or programs which can perform basic as well as the advanced type of operations on the Smartphone.
Q 2) What is the Android SDK?
Answer: To develop a mobile application, Android developers require some tools and this requirement is satisfied by “Android SDK” which is a set of tools that are used for developing or writing apps.
It has a Graphical User Interface that emulates the Android environment. This emulator acts like an actual mobile device on which the developers write their code and then debug/test the same code to check if anything is wrong.
Q 3) What are the different versions of Android OS that you remember?
Answer: Given below are the various versions of Android.
| Version | Name |
|---|---|
| Android 8.0 | Oreo |
| Android 7.0 – 7.1.2 | Nougat |
| Android 6 – 6.0.1 | Marshmallow |
| Android 5 – 5.1.1 | Lollipop |
| Android 4.4 – 4.4.4 | KitKat |
| Android 4.1 – 4.3 | Jelly Bean |
| Android 4.0-4.0.4 | Ice Cream Sandwich |
Q 4) What is the difference between Mobile Application Testing and Mobile Testing?
Answer: Mobile app testing is the testing of applications on a device which mainly focuses on functions and features of the application.
And Mobile Testing is the testing of the actual mobile device and focuses on mobile features like Call, SMS, Contacts, Media Player, inbuilt browsers, etc.
Q 5) Name the languages supported for Android development.
Answer: Java is the widely used language for Android development. It also supports C/C++ and when used with Android SDK, it improves the performance speed too.
Q 6) What are the advantages of the Android Operating System?
Answer: It is open-source and platform-independent. It supports various technologies like Bluetooth, Wi-Fi, etc
Q 7) Define and explain the Android Framework.
Answer: Android framework is a set of API’s using which the Android developers write code for the mobile apps. It contains the methods and classes to write the programming code.
Android framework includes a different set of tools to create image pane, text field, buttons, etc. It also includes “Activities” with which the user interacts and “Services”, which are the programs that run in the background. It is a package of different components like Intents, Broadcast Receivers, Content Providers, etc.
Q 8) Explain briefly – what is meant by Activities?
Answer: Activities are the part of the mobile app which the user can see and interact with.
For Example, if you open an SMS app which has multiple activities like create new SMS, add a contact from the address book, write the content in the SMS body, send SMS to the selected contact, etc.
Activity keeps a track of the following:
- Keeps track of what a user is currently looking for in an app.
- Keeps a track of previously used processes, so that the user can switch between ongoing process and previous process.
- It helps to kill the processes so that the user can return to their previous state
An activity is implemented as a subclass of Activity class as shown below:
Public class MyActivity extends Activity
{
}
Q 9) What is meant by Services?
Answer: Service is an Android component that runs in the background and acts independently. It does not provide any user interface.
Though the services are running behind the scene, a user can continue their work on different apps. Most of the time, the users are not aware of the services which are running in the background. These services allow the system to kill the process without interrupting the user’s ongoing work.
A service is implemented as a subclass of Service class:
Public class MainService extends Service
{
}
Q 10) Explain Implicit and Explicit Intents.
Answer: Implicit Intent calls the system components while Explicit Intents invoke the Activity class.
Q 11) What is the importance of setting up permission in app development?
Answer: Once the permissions are set for the app development, then the data and code are restricted to the authorized users only.
If the code is kept without any restriction or if it is accessible to anyone then there are chances of compromise of code which results in defect leakage.
Q 12) What is .apk extension in Android?
Answer: It is a default file format that is used by the Android Operating System. Application Package Kit (APK) is used for the installation of mobile apps. The .apk contains resource file, certificate, manifest file, and other code.
APK files are archive files in the zip format with .apk extension.
Q 13) What is the database used for the Android platform?
Answer: SQLite is the database that is used for the Android platform. It is an open-source, serverless database.
Q 14) What is ANR in Android?
Answer: ANR stands for Application Not Responding. It is a notification or pop-up displayed by the Android platform whenever the application is performing too many functions at a time and if it is suddenly not responding for a long time to the user action.
Q 15) What is ADB?
Answer: Android Debug Bridge (ADB) is a command-line tool that performs shell commands.
ADB is used for direct communication between the emulator ports. It gives direct control of the communication between the emulator instances to the developer.
Q 16) What is ActivityCreator?
Answer: ActivityCreator is a batch file and shell script which was used to create a new Android project. It is now replaced by the “Create New Project” in Android SDK.
Q 17) What items are important in every Android project?
These are the essential items that are present each time an Android project is created:
- AndroidManifest.xml
- build.xml
- src/
- res/
- assets/
- bin/
Q 18) What language is supported by Android for application development?
The main language supported is Java programming language. Java is the most popular language for app development, which makes it ideal even for new Android developers to quickly learn to create and deploy applications in the Android environment.
Conclusion
Almost all the important Android interview questions and answers have been covered here in this article. I hope that this would have been very useful to you.
I’m sure that you can crack any android interview successfully with a thorough knowledge of all these questions.
I hope you are ready for an Android Studio !! Wish you all success!!
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