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 – 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.
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?
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:
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:
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.
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:
26. How can you launch an activity in Android?
We launch an activity using Intents. For this we need to use intent as follows:
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-
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-
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-
34. Why did you learn Android development?
Learning Android Studio is a good idea because of the following-
35. What are the different ways of storage supported in Android?
The various storage ways supported in Android are as follows:
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:
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.
#android tutorials #android basic interview questions #android basic questions #android developer interview questions #android interview question and answer #android interview questions #android interview questions for experienced #android interview questions for fresher
Getting past the technical and coding interview is not always an easy task for most people.
Lucky for you, there are some amazing resources to help you go through easily and grab that position.
In this article, we will go through some of the best GitHub repositories to help you smash the coding interview.
These collections of repositories are essential in highlighting the different arears to focus on and different topics and questions to expect.
Front-end Developer Interview Questions
This repository is everything that entails frontend development.
Covered content includes:
#coding-interviews #technical-interview-tips #programming-interviews #interview-preparation #interview
In this article, I share what I think is one of the best tips when it comes to design interviews.
As a junior UX designer, I’ve been asked a few times by my peers: what is the most essential UX interview tip I have?
Well, to this question I have a very simple answer,** just be honest**… well, this might sound like a no brainer, but it seems to me that not many junior designers know about it or want to apply it.
I had the chance to speak with a few designers and I discovered that some tend towards being a little bit insincere when going through interviews for design positions. It’s normal to be intimidated when going through an interview process and you might want to act as if you have more experience than you have to secure the job.
Well, I’m here to suggest that that’s not the right approach. I fact, recruiters know in advance that as a junior designer you won’t have many years worth of experience so instead of being insincere it’s better to show up with an open mindset and being honest.
A mindset of learning and improving is always welcomed and valued in today’s world. Simple answers like “I might not know X because I’ve haven’t had the chance to get at it but I can learn it as I’m an avid Lerner” go a long way with recruiters.
Put yourself on your recruiter’s shoes, would you rather employ someone “that answers to 90% of the requirements’’ but doesn’t show a growth mindset, or would you employ someone “that answers to 70% of the requirements’’ but shows it’s the thirst for learning and improving?
That’s not to say that you’ll show up with no qualifications at all. You still have to have a certain level of expertise. “Don’t be the guy with 30hrs of experience using Sketch and 1hr of prototyping experience calling himself a UX designer”.
Some skills can be rapidly learned with just a little bit of discipline and will so don’t be afraid to answer with a no if you haven’t had experience with certain techniques due to lack of opportunity of doing so, for example. It’s always easier to learn something new than being perceived as untrustworthy because you said you were qualified to do something but you finally weren’t.
keep in mind that being sincere is always the way… not just during job interviews but in life. Anytime you’re being insincere to achieve something, most probably, the lie will end catching you back and having the opposite effect you wanted it to have.
Anyway, I’ll stop with my “life lessons” and I’ll wish you a very successful interview.
Hopefully, this little advice does help you.
#design-interview #job-interview #system-design-interview #job-interview-tips #ux-interview
NOTE!_ This challenge is based on the solution from the previous challenge, if you haven’t completed the previous challenge I highly recommend you to do that before continuing with this challenge._
In this challenge you have a list of profiles. Each item on the list is a doctor profile that contains basic information of each doctor and a number of likes.
You have a set of profiles ready to be shown and
ProfileCard component that takes a
profile prop and renders a single profile. You used
v-for directive to iterate through the profiles array render the list.
There are also two button you can use to sort the list.
You were asked to implement additional features to the list, below are the requirements.
#vuejs #interviewing #interview #interview-questions #interview-tips #vue
Svelte Native is a community-led integration that extends NativeScript into the popular new framework known as Svelte. These are exciting times for NativeScript, as today the core team directly supports Angular and Vue.js, with the community offering early support for React and Svelte.
What follows is a brief interview with Svelte Native creator, David Pershouse:
Always been a fan of programming after learning on the Commodore 64. I enjoy all types of programming. I have built games, databases, windows line of business applications.
I was a late comer to Svelte, getting interested in it only when 3.0.0 was in the works. I had used Rich Harris’s RactiveJS for a couple of large customer projects and enjoyed the experience, so I knew that Svelte would be well designed, especially v3. The major version bump would allow those rough edges to be removed that require breaking changes.
I had recently used React/Preact and wanted something that had a smoother developer experience, looking at Vue reminded me very much of Ractivejs and prompted me to look at what Rich was up to. Svelte 3 with its compiler approach and unique handling of reactivity seemed like a step into the next generation of frameworks, so I hopped on board.
I had recently released a mobile game written in preact and PhoneGap/Capacitor and was looking for a “native” mobile framework that would be as easy to deploy to multiple platforms as the PhoneGap solution, but with native speed/features. I wanted the ease and reactivity of modern JS frontend development, but with the cross platform native capability of something like Xamarin/Xamarin Forms. I tried React Native and Flutter before stumbling upon Nativescript-Vue, and through that I was introduced to Nativescript.
Having found Nativescript-Vue, I wanted a similar environment but for Svelte 3. It would also be a good project to teach myself NativeScript and Svelte.
The nice things about Svelte Native are the nice things about Svelte. Svelte Native doesn’t require a special build of the Svelte compiler. It is a small DOM abstraction that the compiled svelte components interface with, and is based on the DOM code found in Nativescript-Vue. Interestingly, due to Svelte’s compiler nature, in the future we could remove the dependency on the DOM abstraction by writing a custom compile target for svelte that would emit Nativescript-core code directly.
Svelte Native also provides an implementation of Svelte’s awesome transition/intro outro system backed by NativeScript’s native transition infrastructure (where possible).
They are definitely supportive. There was mentioned a possible future move to under the svelte namespace and domain for the project site and source. Rich Harris helped out with with the REPL and allowed me to pinch the Svelte site design, and has been quick to fix any svelte bugs/behaviours that impacted svelte-native. They also setup a #nativedev channel on the official Svelte discord server.
Near term is to get compatibility with the professional NativeScript UI components and the new Tab feature of NativeScript 6.0. I would also like to enable HMR support in the default svelte native template.
Medium term is a showcase/examples page to show off apps people have made, and encourage more development.
Long term is to maintain the library to keep it supporting the latest NativeScript and Svelte versions.
#interview #interview-questions #nativescript #david