Let us have a look at some important Android interview questions for beginners.
Android is the world’s most popular mobile platform. Initially developed by Android Inc., which Google bought in 2005, Android was unveiled in 2007. Moreover, the first commercial Android device was launched in September 2008. The core Android source code is known as Android Source Open Project (AOSP), which is primarily licensed under the Apache License.
In this article, will discuss some important Android interview questions for 2019.

But before that, let us have a look at some of the recent Android development trends. Also, we will see the importance of Android developers.
Android development trends

Improved app quality and discovery on Google Play.
Ability to capture audio from different apps in Android Q.
Internet of Things (IoT): Top features include safety, energy, connectivity, and sensing.
Android Jetpack: It is a set of tools, components, and guidance to build the best Android apps capable of running faster.
Android instant apps.
The Kotlin era.
Mobile wallets and payment gateways.
Beacons technology.
Motion and location sensing.
Importance of Android developers
As Android is the most popular operating system, it does have a few bugs. Someone should be able to fix bugs to ensure smooth user experience.
To achieve this, good Android developers are necessary. This is a field that may flourish in the future. And to hire good developers, asking the appropriate Android interview questions is important.


Q1. What are the seven lifecycle methods of Android activity and what is their purpose?

The seven lifecycle methods of Android activity are:
onCreate()
onStart()
onRestart()
onResume()
onPause()
onStop()
onDestroy()
Their purpose is to help structure your code around how you want an activity to perform throughout its lifecycle on the device.
For example, onCreate() is where you would perform your static setup, from creating views to binding data lists. It is always immediately followed by onStart(), where the app will be made visible to the users.



Q2. Briefly list the components of the Android architecture.

This is another top-level question to help you gauge how well the developer understands the big picture of application design. The Android software stack is typically divided into five main components:
Linux kernel: The base layer of an application that directly interfaces with the device hardware — this is the level that deals with hardware drivers like the camera, keypad, and display.
Native libraries: Resting on top of the Linux kernel is a set of open-source libraries, including the SQLite database, libc, and the WebKit browser engine.
Android runtime: The Dalvik Virtual Machine is on the same level as the native libraries and allows every Android app to run its processes.
Application framework: The next layer up provides higher-level services in the form of Java classes to applications on the device. The key services to know are the Activity Manager, Content Provider, Resource Manager, Notifications Manager, and the View System.
Applications: The top layer is the Android app itself. This is the level where you can install applications, and the one developers are most familiar with.



Q3. What is DDMS?

DDMS is short for Dalvik Debug Monitor Server. It ships natively with Android and contains many useful debugging features including location data spoofing, port-forwarding, network traffic trafficking, incoming call/SMS spoofing, thread and heap information, screen capture, and the ability to simulate network speed, state, and latency.


Q4. How would you check for the presence of a Compass sensor on the system using the hasSystemFeature() method?

While it may be tempting to call this method on SensorManager or Sensor, as they both come as part of the Android Sensor Framework, neither of those classes provide the hasSystemFeature() method. These classes find a use for direct access and acquisition of raw sensor data. When it comes to evaluating a system’s capabilities, you can use the PackageManager class to retrieve information on application packages available on a given device. I have written a possible solution for this query:
PackageManager myCompass = getPackageManager();
If(!myCompass.hasSystemFeature(PackageManager.FEATURE_SENSOR_COMPASS))
{
//This device lacks a compass, disable the compass feature.
}
Q5. What is ADB?


This is one of the important Android interview questions.
ADB simply stands for Android Debug Bridge. It presents developers with the power to perform remote shell commands. Its major work is to permit and direct communication towards and from the emulator port.


Q6. Describe activities.

Activities are what you refer to as the window to a user interface. Just as you create windows to display output or to ask for an input in the form of dialog boxes, activities play the same role. Though it may not always be in the form of a user interface.


Q7. What is the importance of XML-based layouts?


The use of an XML-based layout provides a consistent and somewhat standard means of setting the GUI definition format. In common practice, layout details are placed in XML files while other items are placed in source files.


Q8. What do you think are some disadvantages of Android?


Given that Android is an open-source platform and the fact that different Android operating systems have been released on different mobile devices, there’s no clear cut policy on how applications can adapt with various OS versions and upgrades. One app that runs on this particular version of Android OS may or may not run on another version. Another disadvantage is that since mobile devices such as phones and tabs come in different sizes and forms, it poses a challenge for developers to create apps that can adjust correctly to the right screen size and other varying specs and features.
Q9. What’s the difference between a file, a class, and an activity in Android?


File: It is a chunk of arbitrary information or resource for storing information.
Class: It is a compiled form of Java file. Android uses the .class files to produce an executable apk.
Activity: An activity is comparable to a Frame/Window in GUI toolkits. It is not a file or a file type. It is just a class that you can extend in Android for loading UI elements on view.


Q10. What is the Dalvik Virtual Machine?


Dalvik is the name of Android’s virtual machine. The Dalvik VM is an interpreter-only virtual machine that executes files in the Dalvik Executable (.dex) format, a format for effective storage and memory-mappable executions.
The virtual machine is register-based and can run classes compiled by Java language compiler that have been altered into its native format using the included ‘dx’ tool. The VM runs on top of Posix-compliant operating systems depending on it for performing threading and low-level memory management functionalities. The Dalvik core class library provides a familiar development base for those used to programming with Java Standard Edition. But is geared explicitly for the needs of a small mobile device.

I found this article of medium hope that it helps you you can also check this link to read even more questions.




https://medium.com/@nicholaslamar6/top-android-interview-questions-for-beginners-b3438362ff78

I am writing this blog for people why are thinking about learning android application or want to make an application just for fun.
So lest get started with our tutorial.
So What Is Flutter?
Flutter is Google’s mobile app SDK for crafting high-quality native interfaces on iOS and Android in record time. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source. Flutter works on one codebase but results in building native apps for both Android and iOS.
Basic Requirements Before Starting With Flutter
Knowledge of Dart, which is essential for developing Flutter Applications. Learn more about Dart from https://dart.dev/guides.
Architecture of Flutter
Everything is a widget in Flutter App. Flutter gives you a plethora of widgets for building rich UI with powerful functionalities. There may be more than one way of achieving the same UI or functionality in Flutter. Flutter embrace Platform Differences, that means if you want to make your app function in one way in Android but differently in iOS and even if you want to make your app function differently in different device sizes. Flutter works on One Codebase but results in having an app for both iOS and Android, it is just same as Learn Once Write Anywhere.
Comparison between the two giants
Important Resources
https://flutter.dev/docs/development/ui/widgets
https://dart.dev/guides
Spend as much time as possible on flutter widget catalog URL, it will help you to enhance your knowledge and you will stay up to date with community work, you will get to know many possible ways for achieving the same target.
Let’s start with installing Flutter into your system
Reach to website https://flutter.dev/docs/get-started/install
1. Click on your system’s OS, and then download the Flutter SDK.
2. If you are Mac or Linux user:-
3. Extract the file in the desired location, for example:

cd ~/development
#flutter version might be different in your case
tar xf ~/Downloads/flutter_linux_v1.7.8+hotfix.4-stable.tar.xz

Open (or create)
. The file path and filename might be different on your machine.
Add the following line and change
to be the path where you cloned Flutter’s git repo:

export PATH=$PATH:[PATH_TO_FLUTTER_GIT_DIRECTORY]/flutter/bin

Run
to refresh the current window.
Verify that the
the directory is now in your PATH by running:
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echo $PATH

4. If you are Windows User:-
Extract the zip file and place the contained
in the desired installation location for the Flutter SDK (for example,
; do not install Flutter in a directory like
that requires elevated privileges).
Locate the file
inside the
directory. Start it by double-clicking.
From the Start search bar, type ‘env’ and select Edit environment variables for your account.
Under User variables check if there is an entry called Path:
If the entry does exist, append the full path to
using
as a separator from existing values.
If the entry does not exist, create a new user variable named
with the full path to
as its value.
Note that you have to close and reopen any existing console windows for these changes to take effect.
5. Run flutter doctor
From a console window that has the Flutter directory in the path (see above), run the following command to see if there are any platform dependencies you need to complete the setup:content_copy
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2
3

C:\src\flutter>flutter doctor

This command checks your environment and displays a report of the status of your Flutter installation. Check the output carefully for other software you might need to install or further tasks to perform (shown in bold text).
6. You need to setup either Android Emulator or iOS simulator into your device, which is really easy. You can download them from here:-
https://developer.android.com/studio/
https://developer.apple.com/xcode/
To install Android Studio:-
Download and install Android Studio.
Start Android Studio, and go through the ‘Android Studio Setup Wizard’. This installs the latest Android SDK, Android SDK Platform-Tools, and Android SDK Build-Tools, which are required by Flutter when developing for Android.
7. Install VS Code in your System and install extensions named Dart and Flutter

I got this article from this amazing website read full tutorial here [/https://codersera.com/blog/first-flutter-app/]