Introduction To Android Developer Interview Questions
In this section, we will go into details of the various interview questions being faced for an aspiring Android developer. We will start from basic interview questions and move forward towards advanced questions.
Part 1 – Android Developer Interview Questions (Basic)
This first part covers basic Interview Questions and Answers.
Q1. What do mean by Android OS?
Answer:
It is an operating system for mobile, developed by Google, based on a Linux platform and written primarily in Java, used for devices such as smartphones, tablets, etc. With a unique user interface, android is also used in smartwatches, cars, and televisions.
Q2. What do you mean by Android Architecture?
Answer:
The android architecture consists of certain components, which include a software stack. These software stacks carry Linux Kernel, which is a collection of C /C libraries. These libraries are exposed through the application, runtime, and services of the framework. Android architecture’s main components are Linux Kernel, Applications, Application Framework, Android Runtime, and Platform Libraries.
Q3. What is Android Framework?
Answer:
To write and develop applications easily and efficiently, we need an android framework, which consists of several APIs. It incorporates many tools like image panes, text fields, buttons, media players, tools to design UI, phone controls, intents in system tools, etc.
Q4. What is the function of Containers?
Answer:
A container mainly holds widgets and objects. It may also hold buttons, fields, or labels. It is a container for views, which is a collection of multiple view classes.
Q5. What is the purpose of Orientation?
Answer:
To represent a row or as a column for the Linear Layout, one can use the setOrientation() method. It is used to set a value as vertical or horizontal.
Q6. What advantages are there for Android in the current mobile technology?
Answer:
There are many advantages of Android. It is easy to integrate, royalty-free, customizable, open-source advantages, easy access in the android application market, and cost-effective.
Q7. What is ADB in Android?
Answer:
It is Android Debug Bridge, which gives the power to run remote shell commands. From and towards the emulator port, it controls the communication.
Q8. What is API in Android and how does it work?
Answer:
API is an Application Programming Interface, software that works as an intermediate. With which two applications can talk to each other. For example, whenever you are using an app such as WhatsApp or Facebook you are using API.
Q9. What is the function of the Android Library?
Answer:
Its main work is to observe the structure, it is almost the same as the Android app module, but it does not compile code into an android application package, but with an android archive.
Q10. How can you modify a framework?
Answer:
By adding new classes and modifying existing classes one can modify the framework.
Part 2 – Android Developer Interview Questions (Advanced)
Let us now have a look at the advanced Interview Questions.
Q11. How can I control Startup Process?
Answer:
When you boot your android device, if you don’t want an application to auto-start or if you wish to make it freeze, then you can control that from the startup manager.
Q12. What is the situation when the onStop() method gets invoked?
Answer:
In a front of activity, if another activity takes over and if the old activity is not visible to the user, then for the old activity onStop() method gets invoked.
Q13. What does the AndroidManifest.xml file do?
Answer:
Before executing codes, the system should know some basic information about the application, and the root directory information. AndroidManifest.xml file contains this information.
Q14. What is ANR? And when does it occur?
Answer:
UI treads run in Android. When a UI is blocked for a long time then ANR or ’Application Not Responding’ then the error occurs.
Q15. Can you add Platform Libraries?
Answer:
To access device components (physical), like touch input and sensors, we need platform libraries. There are some set of tools available in the Native Development Kit, by which one can use C or C code with android to add platform libraries.
Q16. What is the difference between Notification Manager and Windows Manager?
Answer:
Both are system services, but the notification manager sets down information in the title bar, where a user can expand the bar and set off another activity. But, in a graphical user interface, if a developer wants to control the placement of windows or appearance then we need a windows manager.
Q17. What is the main component in Android Architecture? And why?
Answer:
Linux Kernel is responsible for managing all the drivers of the android architecture. Drivers are mainly required during the runtime, like display drivers, memory drivers, camera drivers, audio drivers, Bluetooth drivers, etc. It is responsible for resource access, memory management, device management, power management, etc. In between the remainder of the stack and device hardware, it provides an abstraction layer. Linux Kernel is the main component in android architecture, and it is impossible to run an application without Dalvik Virtual Machine or DVM.
Q18. What Platform Libraries consists of and how do we use them?
Answer:
It consists of Surface Manager, Media Framework, SSL, SGL, OpenGL, Media Library, Graphics, Web-kit, Freetype, SQLite, etc. For 3D or 2D graphics we need OpenGL SGL and Graphics libraries, for database support, we need SQLite, for display management we need surface manager library, for recording and playing different video and audio format we need media library, for front support we need Freetype, SSL required for internet security, for web browser support we need Web-kit.
Q19. What are the core Components in Android Application architecture?
Answer:
Below are the components of android application architecture:
- Content Providers
- Resource Externalization
- Services
- Notifications
- Intent
Q 20. For an activity, there are four essential states. What are they?
Answer:
- Active: The activity is at the front.
- Paused: If the activity is in the background and still visible.
- Stopped: If the activity is covered by another activity, or if it is hidden or not visible.
- Destroyed: If the activity is completely terminated or if the process is killed.
Each month, users of android, download more than 1.5 billion games and apps. There is much importance of Android in today’s world, as the cost is low for Android, and the performance is better. Because of its open-source framework and its openness, it is much more dearest to developers and consumers.
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This is a guide to Android Developer Interview Questions. Here we have studied the top Android developer Interview Questions and Answers so that the candidate can crackdown the Interview easily. Here in this post, we have studied top Android developer Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –
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