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Android Interview Questions and Answers

Android Interview Questions and Answers

October 30th, 2018

Android Interview Questions and Answers

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Best Android Interview Questions and Answers

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Q1) Is it possible to hold the landscape and portrait mode state, without declaring in the manifest file.

Answer: Yes, can do this from the application by calling registerActivityLifecycleCallbacks in the on Create method.

Q2) Initially Android was developed For?

Answer: It was developed for cameras, later as day to day life mobile is important for the user so switched from cameras to mobiles.

Q3) Why all android version starts with the desert name?

Answer: In order to maintain a good relationship with the user, google name all its version names under the name of the desert.

Q4) From which version request permission is made necessary and why?

Answer: Marshmallow. Because the user has to know what are the permission the application is using.

Q5) Which is the best implementation in sNougat?

Answer: In Nougat they introduced doze. which shows better battery performances and background services, when user never operates mobile.

Q6) What is the latest invention of google in mobiles?

Answer: Google assistant and camera in maps in top models mobiles.

Q7) What Android Logo is designed in Robot?

Answer: Coz, Andy Rubin the founder of Android Inc. was very fascinated to Robots.

Q8) What are the fees that Google gets from user to deploy the application in Play store?

Answer: 25$, for Lifetime.

Q9) Is it necessary to have Clean masters or anti-virus like application in mobiles?

Answer: No, because Android is developed on Linux. Linux is virus free OS.

Q10) Is it possible to change the Startup screen after creating two or three modules?

Answer: Yes, using intent-filter in the manifest screen.

Q11) What are fragments?

Answer: Fragments are those, on which multi-screen can be viewed in a single Activity.

Q12) How to open Google maps in android?

Answer: Using API keys, and calling the onMapReady method.

Q13) What is SQLite?

Answer: It is a lightweight database designed only for Android.

Q14) What are joins that are not supported by SQLite?

Answer: Right outer join and full outer joins

Q15) What is JSON?

Answer: JavaScript object notations is an interface between two applications. Using JSON we can send and receive data.

Q16) Which was the first mobile brand with Android Application?

Answer: First Mobile brand with Android Application was HTC.

Q17) What is the current version of Android and its API?

Answer: The current version of Android is “Pie” (as per Nov 2018) and its API level 28.

Q18) Life cycle of Activity?

OnCreate() – This method is called when the activity is created. It is called only once in activity lifecycle.
OnStart() – This method is called when the activity is getting started, no user interactions will be done at this stage, and this method will be called several times inactivity life cycle depending upon the user navigation. (Loads UI)
OnResume()- On this method call user can interact with the activity and perform actions like a click.
OnPause()- When the other application comes in the foreground, then the activity will get into a pause state.
Ex: When you are using an application ABC and call comes in, where the call application comes in the foreground at this stage your ABC Application will enter into pause stage. When the call is disconnected again your ABC Application will come in the foreground and will move to resume stage.
OnStop()- On stop, the application will stop the activity and user interaction cannot be performed.
OnRestart()- The activity gets restarted and follows the same process.
OnDestroy()-The activity will be killed by the system

Q19) When the application is in the foreground and you get a call, in what stage your application will get into?

Answer: OnPause

Q20) Difference between nonstop() and destroy() methods in activity lifecycle?

Onstop() -It will temporarily call the destroy instance of activity to provide space for other applications.
OnDestroy()- Application will finish and shut down the activity.

Q21) What is fragment and Lifecycle of Fragments?

Answer: A fragment can be called as a mini activity which is called inside the Activity. You can add and remove fragment while activity is running.

Q22) What is android Manifest.xml?

Answer: Android manifest .xml is an XML file which contains all the activities, services details, and permissions defined in it. It contains all the essential information about our applications.

Q23) Can Android Application be programmed only in Java?

Answer: Yes, Android application can be programmed in other languages like NDK, C, C++, and Kotlin also.

Q24) What is Intent? Difference between Implicit Intent and Explicit Intent?

Answer: The intent is used to perform an action inside the activity or to link one activity to another activity.
Implicit Intent: Performs action inside the same class such as calling webview, send SMS, call etc.
Explicit Intent: It is used connect from one activity to another.

Q25) Where do you define the icon for your activity?

Answer: <activity android:icon=”@drawable/app_icon” android:name=”.MyTestActivity”></activity>
Where the image is saved in drawable folder.

Q26) What is ANR notification in android and when do you get that error?

Answer: Application Not Responding is the exception raised when the too much of work is done on the main thread.

Q27) Enumerate three key loops when monitoring the activity?

Entire lifetime – activity between onCreate and onDestroy
Foreground lifetime – activity between onResume and onPause.
Visible lifetime – activity between onStart and onStop

Q28) How can ANR be prevented?

Answer: Stop doing heavy jobs on the main thread. The Instead use worker threads such as IntentService, AsyncTask or another Thread.

Q29) How to convert your code into a .apk file?

Answer: Build-> Build APK(s)

Q30) What is Service? When do you use it?

Answer: Service is a component that runs in the background to perform long-run operations. There are 2 types of service
Bound: It is called when the application is running and killed when the application is killer. It is bound with the application.
UnBound: It runs in the background even when the application is not running /killed.
Service is called by extending the activity with the keyword “Service”
Ex: To track the delivery boy, even if the application is not being used it will run in the background.

Q31) What is BroadCast Receiver? When do you use it?

Answer: The broadcast receiver is used to receive the broadcast messages from other applications or within the application.
Ex: Reading OTP, we check the incoming SMS using a broadcast receiver.

Q32) What is Content, Provider? When do you use it?

Answer: The content provider is used to sharing data between two or more different applications.
Ex: sharing data between cab user and driver application

 Q33) What is Intent Filter? When do you use it?

Answer: The intent filter defines the type of intent to which activity, services, and broadcast receivers can respond.
Ex: In Manifest.xml we define the <intent filter> to define which activity as to be launched first.

Q34) Difference between styles and themes?

Answer: Styles is a set of field attributes and values which is applied to the element called.
A theme is set of field attribute and values which is applied for the whole application once called.

Q35) Difference between ArrayList and Hash<Map>?

ArrayList :
1.ArrayList is inserted in an order.

  1. Data is fetched from ArrayList depending upon the index.

3.ArrayList allows duplicate values.
4. It is represented by ArrayList keyword.
Hash<Map> :

  1. HashMap is stored data in the key, value pair
  2. Data is fetched from hashmap using key

3. Hashmap does not allow duplication
4. It is represented by Hash<Map>

Q36) What are the different types of storage in android?

Answer: Android uses 3 types of storage:
Shared Preference: It stores small data. Shared Preferences allow you to save and retrieve data in the form of key, value pair.
Files: It stores data in text, .mp3,mp4,.png,.jpg format, fetching data among the same type of data is difficult.
Sqlite Database: It overcomes the disadvantages of shared preference and files. It can store any type of data, update, delete easily. Sqllite storage depends on our mobile storage capacity.

Q37) Difference between Rest and Soap?


  1. Uses XML, text, HTML and Jason format to send and receive data.
  2. Security is less than soap
  3. Transfers data through HTTP only.
  4. Performance is better than Soap since it uses less CPU
  5. It doesn’t need much bandwidth
  6. Rest can make use of Soap


  1. Uses XML only for sending and receiving data.
  2. It is more secure than rest.
  3. Transfers data through HTTP ,SMTP,FTP etc.
  4. Performance is not better than rest.
  5. It needs more bandwidth for users.
  6. Soap cannot use Rest.

Q38) What is Async Task and methods of Async Task?

Answer: Async task is a class that extends object class to allow short operations to run asynchronously in the background. Async task runs in a new thread.
Methods of Asynctask are :
1.onPreExecute: a step used to set up the task
2.doInBackground: a step used to perform the actual task
3.onProgressUpdate: a step used to update the current progress status of the task that is being performed in doInBackground
4.onPostExecute: once doInBackground finishes executing the task, this step delivers the result back to the main UI thread and stops the AsyncTask process

Q39) What is Shared Preference and Write its Syntax?

Answer: Shared Preference is used to store and retrieve small data like login details in the form of key-value of the pair.
To save data in SharedPreference:

Editor edit=SharedPreferences();

To retrieve data from shared Preference:
SharedPreferences share = new SharedPreference(key,Context.Mode_Private);

Q40) What is RecyclerView ?

Answer: RecyclerView is an advanced and more flexible version of listview where single view using its custom adapter can replace listview and gridview by maintaining limited number of views and optimized memory usage.

Q41) Difference between RecyclerView and Listview/Gridview?

1. Horizontal scrolling is supported.

  1. Recycler can be used as a list or grid format depending on the requirement.

3. Recyclerview gives optimized memory usage, it will allocate data only to the list of data shown on screen and extra 2 on top and bottom of the list.
1. Horizontal scrolling is not supported.
2. Listview cannot be used as gridview.
3. It allocates memory for all the items in the list and hence memory is not optimized.

Q42) What is Card View?

Answer: Card view is a UI element which displays the data in card format with corner radius and drops shadow elevation.

Q43) What are SQLite and its methods?

Answer: SQLite is a relational open source database which comes inbuilt in android devices which enables you to store, retrieve, manipulate and delete data.
Using SQLite android application can run in offline mode also.
Sqlite is implemented in our project by extending the class with SqliteOpenHelper class which overrides 2 methods i.e;
1.oncreate() -Where the database is created along with its version.
2.onUpgrade() -It is supporting function of onCreate() when the version has updated the changes in a database will be performed in an on upgrade method without disturbing the existing one.

 Q44) How to integrate firebase?

Answer: Firebase gives you tools and infrastructure from Google to help you develop, Firebase provides several API where each one performs their own functions and can be utilized in our application. Let us see basic steps to integrate firebase which will be same initial steps for all the firebase API integrations.
Step1: Go to tools in your project and select firebase where it shows all the firebase api’s or goes to Developer.Firebase.com (https://console.firebase.google.com/u/0/?pli=1) and register your application/project
Step2: Now select the api you want to integrate and add the details of your project and register the api ex: We are implementing Crash analytics
Step 3: Download the google-service.json file provided and place it inside your project app folder
Step 4: Go to tools -> Firebase and you see the firebase API connected and follow the next process which adds the dependency into your application or dependencies can be added manually also by following the document.
Step 5: Now your firebase integration is ready where u can use this log in your code and can see in firebase account.

Q45) How to integrate Facebook into our application?

Step1: Go to Developer.facebook.com and create your project.
Step 2: Make sure your grade contains jcenter() if it doesn’t exist add it.
Step 3: Add dependency in our app gradle file and build project
implementation ‘com.facebook.android:facebook-login:[4,5)’
Step 4:Open your /app/res/values/strings.xml file.
<string name=”facebook_app_id”>**********62401</string>
And your facebook app_id .
Step 5: Open your manifest add internet permission:
<uses-permission android:name=”android.permission.INTERNET”/>
Step 6: Add metadata file inside your manifest .xml file inside application tag
<meta-data android:name=”com.facebook.sdk.ApplicationId”
<activity android:name=”com.facebook.FacebookActivity”
android:label=”@string/app_name” />
<action android:name=”android.intent.action.VIEW” />
<category android:name=”android.intent.category.DEFAULT” />
<category android:name=”android.intent.category.BROWSABLE” />
<data android:scheme=”@string/fb_login_protocol_scheme” />
Step7: Add your package name, and the activity name where the facebook login button will be used.
Step 8: Generate key hash , there are several ways to generate keyhash one among them are as follows, run this set of code in an application where it generates the keyhash in log or toast, copy the keyhash code and place it in developers account
public void generateHashkey(){
try {
PackageInfo info = getPackageManager().getPackageInfo(getPackageName(), PackageManager.GET_SIGNATURES);
for (Signature signature : info.signatures) {
MessageDigest md = MessageDigest.getInstance(“SHA”);
String hashKey = new String(Base64.encode(md.digest(), 0));
} catch (NoSuchAlgorithmException e) {
Log.e( “hashkey”, String.valueOf(e));
} catch (Exception e) {
Log.e(“hashkey”, String.valueOf(e));
Step 9: Add a facebook login button in the activity mentioned
android:layout_marginBottom=”30dp” />
Step 10: Add the following set of code which is given step by step in facebook doc and looks like this in the end .
public class MainActivity extends AppCompatActivity {
//Facebook Login in
CallbackManager callbackManager;
//Initializing textview
TextView userdetails;
protected void onCreate(Bundle savedInstanceState) {
//CallbackManager of facebook -REFER Developer.Facebook.com and follow as per the instruction
callbackManager = CallbackManager.Factory.create();
//Initializing facebook login button
LoginButton loginButton = (LoginButton) findViewById(R.id.login_button);
//Permission for the user to his email and other details
//On click of facebook login button calls the method getUserdetails
loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
public void onSuccess(LoginResult loginResult) {
//Prints accessToken (optional) for facebook login
AccessToken accessToken = loginResult.getAccessToken();
//Prints the login userdetails provided by FB.
//On cancel click of fetching data
public void onCancel() {
// App code
//On error in fetching userdetails from facebook api
public void onError(FacebookException exception) {
// App code
//callback manager call back method
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
callbackManager.onActivityResult(requestCode, resultCode, data);
//response of userdetails provided by facebook
protected void getUserDetails(LoginResult loginResult) {
GraphRequest data_request = GraphRequest.newMeRequest(
loginResult.getAccessToken(), new GraphRequest.GraphJSONObjectCallback() {
public void onCompleted(
JSONObject json_object,
GraphResponse response) {
/* Intent intent = new Intent(MainActivity.this, UserDetails.class);
intent.putExtra(“userProfile”, json_object.toString());
Bundle permission_param = new Bundle();
permission_param.putString(“fields”, “id,name,email,picture.width(120).height(120)”);
protected void onResume() {
// Logs ‘install’ and ‘app activate’ App Events.
protected void onPause() {
// Logs ‘app deactivate’ App Event.

Q46) Difference between Picasso and glide?


  • Doesn’t support gif image.
  • Downloads the image and stores a full image in cache.
  • Less memory efficient compared to Glide.

Glide :

  • Supports Gif images.
  • Downloads the image, resize it to imageview size and stores in a disk cache.
  • More memory efficient.

Q47) Difference between volley and Retrofit?


  • Volley as caching mechanism
  • Volley enables retry policy
  • In Volley, JSON response is parsed manually.
  • Volley as inbuilt image loader support


  • Retrofit doesn’t have caching mechanism
  • Retrofit doesn’t support retry policy.
  • Volley supports automatic parsing.
  • Retrofit doesn’t have inbuilt image loader support, which can be performed by using Picasso/glide library.

Q48) What is web service and how do you achieve it?

Answer: Webservice is a means of communication between your application and the server, where the data sent from the application is stored into the server and data stored in the server is retrieved by the application. Web Service uses Soap or REST as a means of communication.
Webservice in android can be achieved by making API call. To make an API call we can use libraries like volley, retrofit, and OK HTTP etc.

 Q49) What is Service and types of services?

Answer: Service is an Android component which runs in the background even when the application that started service is destroyed.
There are two types of service :
1.Bound Service – It is bound with the application and destroyed when the application or service is killed.
2.UnBound Service -It is not bound with the application, once the service is started it runs in the background even when the application which started the service is destroyed.

Q50) What is a singleton and what is its use?

Answer: Singleton ensures only single instances/object will be created which can be used by all the other classes. It helps save memory since only one object is created.

Q51) What is a broadcast receiver?

Answer: Broadcast Receivers are one which receives the message from other application or system itself.
Ex: The notification which we get when a battery is charged.

Q52) How to make a responsive application which is used in mobile and tablet?

Answer: The application can be made responsive my creating two different layouts with same name and id’s.
res/layout/main_activity.xml           # For phones
res/layout/main_activity_tablet.xml    # For tablets
And calling it in your java class.
public class MyActivity extends Activity {
@Override protected void onCreate(Bundle savedInstanceState) {
Configuration config = getResources().getConfiguration();
if (config.smallestScreenWidthDp >= 600) {
} else {

Q53) What is the limit of data storage in sqlite?

Answer: Maximum data SQLite can store depends on the storage space of your device.

Q54) What is intent service?

Answer: Intent Service is used in the long task where there is no communication with the main thread. Intentservice runs on a separate worker thread.

Q55) What is the use of Bundle savedInstanceState?

Answer: savedInstanceState is a method parameter of on creates a method which saves the state of the activity.
Ex: When the activity goes into the background the state of the activity will be paused, which is stored in savedInstanceState and helps to revoke the activity from the same state.

Q56) What is Android?

Answer: It is an open source operating system that is primarily used on mobile devices such as mobile phones and tablets. It is a Linux kernel-based system that contains rich components that allow developers to create and run applications that can do basic and advanced functions.

Q57) What is Google Android SDK?

Answer: Google Android SDK is an instrument that developers need to encrypt and write to applications on Android-enabled devices. It has a graphical interface system that enables the Android-enabled environment to check their code and fix them.18) What is the Android Architecture?
Android architecture consists of 4 main components:
Linux kernel

  • Libraries
  • Android architecture
  • Android apps

Q58) Describe the Android Framework

Answer: The main feature of Android Framework is Android Framework. All classes and methods required by developers to view applications in Android environment can be found here.

Q59) What is AAP?

Answer: AAPT shortened to Android property packaging tool. This tool provides developers with the ability to handle zip-compatible archives, including the creation, extraction and viewing of its contents.

Q60) What is the importance of keeping Emulator in the Android environment?

Answer: The developer creates a “drama” around an interface that acts as a real mobile device. They can write and test codes, and even bug. They are a safe place for testing numbers in the initial design phase.

Q61) What is the functional mode?

Answer: A new creative operating system is the first step to building a new Android project. It was created by the shell script used to create the new file system system necessary for the characters in the Android IDE.

Q62) describe the functions?

Answer: You specify the functions as a window for the user interface. As you create windows, actions always play the same role, although this is not always in the form of user interface.

Q63) What is Intents?

Answer: Nokia displays the notification messages from Nokia’s Android device. This is used to warn users of a given state. Users can respond to users.

Q64) Different activities from services.

Answer: Operations can be completed or the user can stop at anytime. On the other hand, designed to run behind the scenes, and can operate independently. Most services run continuously, regardless of whether or not some or any action is taken.

Q65) What is important in every Android plan?

Each year this is an Android plan created by the vital products:
• with AndroidManifest.xml
• build.xml
• post /
• Source /
• Res /
• Assets /

Q66) What is the importance of XML-based layouts?

Answer: The use of XML-based layouts provides a standard and somewhat stable algorithm that designs the GUI definition. In general practice, XML files contain layout details, other products are placed in source files.

Q67) What are the containers?

Answer: Containers, as the name suggests, contain objects and widgets, based on the specificity of the goods and the specific arrangement. Containers, labels, fields, buttons or baby containers can be taken.

Q68) What’s the direction?

Answer: SetOrientation () can be set using the Direction, LinearLayout if a line or a program is specified. Values set to HORIZONTAL or VERTICAL.

Q69) What is the importance of Android in the mobile market?

Answer: Developers can create and write applications that run under the Android environment. That means, every mobile device in Android enabled can support and run these apps. With the growing popularity of Android mobile devices, developers can use this trend by distributing it to anyone who wants to create their apps on Android Market.

Q70) What is AAPT?

Answer: AAPT shortened to Android property packaging tool. This tool provides developers with the ability to handle zip-compatible archives, including the creation, extraction and viewing of its contents.

Q71) What are the containers?

Answer: Containers, materials and widgets, depending on the specific products and depending on what specific design is needed. Containers contain labels, ports, buttons or baby containers.

Q72) What is the importance of default resources?

Answer: If there are no default sources that contain the default strings and files, the error will not work and the application will not work

Q73) When dealing with many sources, will a priority take place?

Answer: If you think that this will have multiple resources that fit the architecture of a device, ‘Logel’ qualification will always take the highest priority on others.

Q74) When will the HR?

Answer: An ANR dialogue will be shown to users based on two potential conditions. Without a response to an input event within 5 seconds, the broadcaster did not act within a second 10 and 10 seconds.

Q75) What is AIDL?

Answer: AIDL, or Android Interface Definition Language, handles the interface requirements, so both can interact with the interprocess communication or IPC simultaneously. This process involves breaking Android comprehensible raw materials. This part is required because a process can not access memory of other processes.

Q76) What types of data are supported by AID?

AIDL support for the following data types is:

  • string
  • charSequence
  • List
  • Map
  • All native Java data types are int, long, char and boolean

Q77) What is a piece?

Answer: A piece is part or part of a function. You can move or combine it with other functions, not just in a sense. The pieces are used again.

Q78) What is the observable function?

Answer: A transparent function is as follows. It really knows the user, but not necessarily in the front.

Q79) When is the best time to take a lead step?

Answer: The most important of all other states is the killing or completion of the leading action, the ultimate instrument

Q80) Can I use or add a part without using the user interface?

Answer: Yes, it can be done when you want to create a playback for a particular function. You can do this by adding (piece, string) method to add a piece of functionality.

Q81) How do you remove the icons and widgets from the main screen of the Android device?

Answer: To remove the icon or shortcut, press and hold the icon. Drag down the bottom of the screen that appears to remove the button.

Q82) What are the key elements under the Android App Framework?

There are 5 main components under the Android App Framework:

  • Services
  • Purpose
  • External output
  • Announcements
  • Content Providers

Q83) What is a sticky purpose?

Answer: A Sticky Note is a broadcast from SendStickyBroadcast () mode, whereby the purpose is to roll around after the broadcast, allowing it to collect data from others.

Q84) Do all mobile phones support the latest Android OS?

Answer: Some Android-powered phones allow you to upgrade the higher Android operating system version. However, not all updates will allow you to get the latest version. Can it support new features under the latest Android version, depending on the phone’s ability and specs?

Q85) What is a portable wi-fi hotspot?

Answer: The portable Wi-Fi hotspot allows you to share your mobile internet connection on the other wireless device. For example, using, you can use your laptop to connect to the Internet using that access point.

Q86) What is an action?

Answer: In Android Development, the sender of the action is expected to do what he / she wants to do. Most utility function is based on planned operation.

Q87) What is the difference between regular bitmap and nine patch?

Answer: Usually, a nine-link image allows reuse, which can be used for background device or other image size requirements. Nine Patch refers to the way you can change the size of the image: 4 corners that are unscaled, 4 edges that are measured in axis, and the middle one that can be measured on two axes.

Q88) What language is supporting for application development?

Answer: Java language programming language is the key language. Apple is the most popular language for the application, which makes it ideal for new Android developers to quickly create applications and build new ones in the Android environment.

Q89) What is Android?

An open source working framework which is fundamentally utilized on cell phones, for example, cell phones and tablets. Its framework depends on Linux bit which is outfitted with segments that enable engineers to construct and run applications that can execute both fundamental and propelled capacities.

Q90) What is Android Architecture?

Android Architecture is created upon four key segments:

  • Libraries
  • Linux Kernel
  • Android Framework
  • Android Applications

Q91) What Is the Google Android SDK?

The Google Android SDK is a toolset that engineers require so as to compose applications on Android empowered gear. It contains a graphical interface that copies an Android-driven handheld condition, empowering them to test and investigate their codes.

Q92) Tried to move toward becoming Android?

Investigate the post to find the ability on Android Training.

Q93) Depict the Android Framework.

The Android Framework is a vital component of the Android Architecture. Where you can discover every one of the techniques and classes that designers would require so as to compose applications on the Android condition.

Q94) What is AAPT?

AAPT is an abbreviation for Android Asset Packaging Tool. This instrument stipends designers with the ability to manage zip-good chronicles, which fuses making, separating just as survey its substance.

Q95) For what reason is it vital to have an emulator inside the Android condition?

The emulators enable designers to compose, test codes, investigate and “play” around an interface which goes about as a genuine cell phone. Emulators are a safe and safe spot for testing codes, particularly in the underlying structure stage.
Portray Activities.
Exercises are something you allude to as the window to a UI. Thus, as you request contribution to the type of exchange encloses or make windows request to show yield, exercises assume the comparative job, however it may not generally be as a UI.

Q96) What is the utilization of an ActivityCreator?

An ActivityCreator is really the underlying advance to the improvement of another android venture. It’s developed of a shell content that will be utilized to produce new document framework structure fundamental for composing codes inside the Android IDE

Q97) What are Intents?

Aims are activities to be performed, they show message warnings to the client inside the android empowered gadget. They can be utilized to alert client about the cautions of a specific state which happened

Q98) Separate Activities from Services.

Exercises can be ended or shut whenever the client wants. Further administrations are intended to keep running in the behind the stage and can act independently. Most administrations keep running without intrusions, paying little heed to whether there are sure or no exercises are really executed.

Q99) What are the benefits of Android receiving?

The fundamental preferred standpoint of embracing Android is
It offers a brought together way to deal with application advancement.
Designers need produce for Android, and their applications ought to have the capacity to keep running on various distinctive gadgets, as long as the gadgets are fueled utilizing Android. In the realm of cell phones, applications are the most critical piece of the achievement chain.
Gadget makers, in this way, consider Android to be their best would like to test the assault of the iPhone, which as of now directions a substantial base of uses

Q100) How to ‘Begin Another Activity’?

Purpose I = new Intent(getApplicationContext(), Activity2.class); startActivity(i);

Q101) Name a few special cases in android?

  • Inflate Exception
  • Surface.OutOfResourceException
  • SurfaceHolder.BadSurfaceTypeException
  • WindowManager.BadTokenException

Q102) Is it conceivable to make a movement in Android without a UI?

Truly, an action can be made with no UI. These exercises are treated as unique exercises.

Q103) What is the contrast among Service and IntentService? How is each utilized?

Administration is the base class for Android benefits that can be stretched out to make any administration. A class that straightforwardly broadens Service keeps running on the primary string so it will hinder the UI (if there is one) and ought to in this way either be utilized just for short errands or should make utilization of different strings for longer assignments.
IntentService is a subclass of Service that handles nonconcurrent demands (communicated as “Goals”) on interest. Customers send asks for through startService(Intent) calls. The administration is begun as required, handles every Intent, thusly, utilizing a laborer string, and stops itself when it comes up short on work. Composing an IntentService can be very basic; simply expand the IntentService class and supersede the onHandleIntent(Intent intent)method where you can deal with every single approaching solicitation.

Q104) What is the contrast between a normal bitmap and a nine-fix picture?

When all is said in done, a Nine-fix picture permits resizing that can be utilized as foundation or other picture estimate prerequisites for the objective gadget. The Nine-fix alludes to the manner in which you can resize the picture: 4 corners that are unscaled, 4 edges that are scaled in 1 pivot, and the center one that can be scaled into the two tomahawks.

Q105) What is an unmistakable movement?

An unmistakable movement is one that sits behind a forefront exchange. It is really noticeable to the client, yet not really being in the closer view itself.

Q106) What is a Fragment?

A piece is a section or bit of a movement. It is particular it could be said that you can move around or consolidate with different sections in a solitary action. Parts are additionally reusable.

Q107) At the point when does ANR happen?

The ANR discourse is shown to the client dependent on two conceivable conditions. One is when there is no reaction to an info occasion inside 5 seconds, and the other is the point at which a communicate recipient isn’t finished executing inside 10 seconds.

Q108) What is the AndroidManifest.xml?

This document is basic in each application. It is proclaimed in the root registry and contains data about the application that the Android framework must know before the codes can be executed.

Q109) In what manner can the ANR be counteracted?

One strategy that keeps the Android framework from finishing up a code that has been in charge of an extensive stretch of time is to make a kid string. Inside the tyke string, a large portion of the genuine operations of the codes can be set, so the principle string keeps running with negligible times of lethargic occasions.

Q110) At the point when is the onStop() technique conjured?

A call to onStop technique happens when a movement is never again noticeable to the client, either on the grounds that another action has assumed control or if before that action.

Q111) What is include?

Adb is short for Android Debug Bridge. It permits designers the ability to execute remote shell directions. Its fundamental capacity is to permit and control correspondence towards and from the emulator port.

Q112) Separate Activities from Services

Exercises can be shut or ended whenever the client wishes. Then again, administrations are intended to keep running in the background and can act freely. Most administrations run persistently, paying little heed to whether there are sure or no exercises being executed.

Q113) Which segments are important for a New Android venture?

At whatever point another Android venture is made, the underneath segments are required:
show: It contains XML record.
fabricate/: It contains assemble yield.
src/: It contains the code and asset records.
res/: It contains bitmap pictures, UI Strings, and XML Layout for example all non-code assets.
resources/: It contains a record which ought to be assembled into an .apk document.
The beneath picture demonstrates the Project View once an Android venture is made:

Q114) Give a case for sticky communicate.

Here’s a precedent: When you call registerReceiver() for that activity — even with an invalid BroadcastReceiver — you get the Intent that was the last communicated for that activity.
Henceforth, you can utilize this to discover the condition of the battery without essentially enlisting for all future state changes in the battery.

Q115) What is DDMS?

DDMS represents Dalvik Debug Monitor Server. It gives the accompanying cluster of troubleshooting highlights:

  • Port sending administrations
  • Screen catch
  • String and pile data
  • System traffic following
  • Area information ridiculing

Q116) Name a few special cases in android?

Blow up Exception

Q117) Give the vital center parts of Android.

The center segments of Android working frameworks are:

  • Activity
  • Intents
  • Services
  • Content Provider
  • Fragment

Q118) Enumerate the means in making a limited administration through AIDL.

  • make the .aidl document, which characterizes the programming interface
  • actualize the interface, which includes broadening the internal dynamic Stub class just as embedding its strategies.
  • uncover the interface, which includes actualizing the support of the customers.

Q119) What is the significance of Default Resources?

At the point when default assets, which contain default strings and documents, are absent, a mistake will happen and the application won’t run. Assets are set in extraordinarily named subdirectories under the venture res/catalog.

Q120) When managing numerous assets, which one outweighs everything else?

Expecting that these numerous assets can coordinate the setup of a gadget, the ‘area’ qualifier quite often takes the most noteworthy priority over the others.

Q121) When does ANR happen?

The ANR exchange is shown to the client dependent on two conceivable conditions. One is when there is no reaction to an info occasion inside 5 seconds, and the other is the point at which a communicate collector isn’t finished executing inside 10 seconds.

Q122) What is AIDL?

AIDL, or Android Interface Definition Language, handles the interface necessities between a customer and an administration so both can convey at a similar dimension through interprocess correspondence or IPC. This procedure includes separating objects into natives that Android can get it. This part is required just on the grounds that a procedure can’t get to the memory of the different procedure.

Q123) What information types are bolstered by AIDL?

AIDL has support for the accompanying information types:

  • string
  • charSequence
  • List
  • Map
  • all local Java information types like int, long, roast and Boolean

Q124) Which are the discourse boxes upheld by the Android stage?

Android underpins four kinds of exchange boxes:

  • AlertDialog: It has a limit of 3 catches and now and then AlertDialog incorporates checkboxes and Radio catches to choose the component.
  • ProgressDialog: It shows the advancement bar or wheels.
  • TimePickerDialog: Using this discourse box, a client chooses the Time.
  • DatePickerDialog: Using this exchange box, a client chooses the Date

Q125) Which instruments are utilized for investigating on the Android stage?

To comprehend the reason for the disappointment or reason for any issue, troubleshooting is critical. On the Android stage Android Monitor.bat utility is utilized while on the iOS stage, iPhone Configuration utility is utilized for troubleshooting purposes.
There are distinctive apparatuses for investigating which incorporate – Android DDMS, Android Debug Bridge, iOS test system, Debugging from Eclipse with ADT, Remote troubleshooting on Android with Chrome and so on.

Q126) Which situation can test just on genuine gadgets however not on emulator?

Emulators are utilized for performing comparative sort of testing which is performed on the genuine gadgets. Fundamentally, emulators are utilized as a trade for genuine gadgets as once in a while genuine gadgets are not accessible for testing, utilization of genuine cell phones for testing reason for existing is costlier on occasion.
Yet, there are couple of situations which can’t be tried utilizing an emulator, these can be tried just utilizing genuine gadgets. These situations are interfered with situations for example message, telephone consider intrusion while utilizing the application, low battery, Bluetooth, memory card mount and unmount and so on.

Q127) How would you investigate android application which is slamming as often as possible?

Given beneath are the few stages that we have to pursue while investigating the slamming issue:

  • Free up memory space: There is just a constrained space accessible on the cell phones for versatile applications. To abstain from slamming issue or memory related issue, you have to initially check the memory space.
  • Clear application information utilization: You can clear the application information utilizing the Application Manager under “Settings”. This will clear the store memory and enable some free space to introduce another application or it will help up your current application.
  • Memory Management: Some applications run splendidly on one sort of cell phone however the equivalent application may not deal with another kind of gadget concerning such gadgets the handling power,

memory the board and CPU speed is extraordinary. For any application to run appropriately on a cell phone, you ought to deal with the memory on the gadget.

  • Compatibility issue: It is dependably impractical to test a versatile application on every single cell phone, programs, working frameworks and so on. So you have to test your portable application on the greatest number of cell phones as you can so as to maintain a strategic distance from any similarity issue.

Q128) What are Runtime Permission and its sorts?

Prior to API 23 (Marshmallow 6.0) the asked for authorizations are introduced to the client before introducing the application. The client needs to choose if these authorizations will be given to the application.
In the event that the client denies required consent, the related application can’t be introduced. The check of the consent is just performed amid establishment. Consents can’t be denied or conceded after the establishment.
Android 6.0 Marshmallow (API 23) presented another runtime authorization display. On the off chance that your application targets Android 6.0, you should utilize the new consents display. Runtime Permission will check whether the Permission is conceded or not at runtime(For model, when a client opens the camera, at that point just it will inquire as to whether as of now not gave).

Q129) At the point when does ANR happen?

The ANR exchange is shown to the client dependent on two conceivable conditions. One is when there is no reaction to an info occasion inside 5 seconds, and the other is the point at which a communicate beneficiary isn’t finished executing inside 10 seconds.

Q130) What is AIDL?

AIDL, or Android Interface Definition Language, handles the interface necessities between a customer and an administration so both can convey at a similar dimension through interprocess correspondence or IPC. This procedure includes separating objects into natives that Android can get it. This part is required essentially on the grounds that a procedure can’t get to the memory of alternate process.

Q131) What information types are bolstered by AIDL?

AIDL has bolster for the accompanying information types:

  • string
  • charSequence

Q132) Is it conceivable to utilize or include a part without utilizing a UI?

Truly, it is conceivable to do that, for example, when you need to make a foundation conduct for a specific movement. You can do this by utilizing add(Fragment, string) strategy to include a section from the movement.

Q133) How would you expel symbols and gadgets from the principle screen of the Android gadget?

To expel a symbol or alternate route, press and hold that symbol. You at that point drag it downwards to the lower some portion of the screen where an evacuate catch shows up.

Q134) What are the center parts under the Android application engineering?

There are 5 key parts under the Android application engineering:

  • administrations
  • purpose
  • asset externalization
  • notices
  • content suppliers

Q135) What forms a common Android application venture?

A task under Android advancement, upon accumulation, turns into an .apk document. This apk record design is really comprised of the AndroidManifest.xml document, application code, asset records, and other related records.

Q136) What is a Sticky Intent?

A Sticky Intent is communicated from sendStickyBroadcast() strategy with the end goal that the purpose coasts around even after the communicate, enabling others to gather information from it.

Q137) Do every cell phone bolster the most recent Android working framework?

Some Android-controlled telephone enables you to move up to the higher Android working framework adaptation. In any case, not all overhauls would enable you to get the most recent form. It depends to a great extent on the ability and specs of the telephone, regardless of whether it can bolster the more up to date includes accessible under the most recent Android rendition.

Q138) What is a versatile wi-fi hotspot?

Versatile Wi-Fi Hotspot enables you to share your portable web association with another remote gadget. For instance, utilizing your Android-controlled telephone as a Wi-Fi Hotspot, you can utilize your PC to interface with the Internet utilizing that passage.

Q139) What is the activity?

In Android advancement, activity is the thing that the purpose sender needs to do or expected to get as a reaction. Most application usefulness depends on the planned activity.

Q140) What is the contrast between an ordinary bitmap and a nine-fix picture?

All in all, a Nine-fix picture permits resizing that can be utilized as a foundation or other picture measure necessities for the objective gadget. The Nine-fix alludes to the manner in which you can resize the picture: 4 corners that are unscaled, 4 edges that are scaled in 1 hub, and the center one that can be scaled into the two tomahawks.

Q141) What language is bolstered by Android for application improvement?

The principle language bolstered is the Java programming language. Java is the most prevalent language for application advancement, which makes it perfect notwithstanding for new Android engineers to rapidly figure out how to make and send applications in the Android condition.