Top 10 Android Interview Questions for Freshers 2016

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 Android Development is very popular option as the career for freshers of Computer/IT students. There are many vacancies available in market for Android Developer but there is very big challenge to crack android development interview. we should have basic knowledge of core JAVA and Android. Let’s explore all kind of android development interview questions and Answers which may be asked by interviewer in your next interview. 

Basic/Essential Android Interview Questions and Answers

What is Android?

Android is a complete set of software and open source Linux-based operating system for Smartphones, Tablets, Smart TVs, Cars, Smart Glasses, and Watches.It is developed by Google and later the OHA (Open Handset Alliance). In android development, Java language is mostly used to write the android code even though there are many other options are available. The purpose of making android project is to create a successful real-world product that improves and completely change the mobile world experience for end users.

Detail Explanation- Click Here

Who is the founder of Android?

At the starting point, Android Incorporation founded by Andy Rubin in Palo Alto, California, the United States in October 2003. Google bought android Incorporation in 17th August 2005. Since then, it becomes the subsidiary of Google Incorporation. The key employees of Android Incorporation are Andy Rubin, Rich Miner, Chris White and Nick Sears.

Detail Explanation- Click Here

What are the code names of android?

  1. Aestro
  2. Blender
  3. Cupcake
  4. Donut
  5. Eclair
  6. Froyo
  7. Gingerbread
  8. Honycomb
  9. Ice Cream Sandwitch
  10. Jelly Bean
  11. Kitkat
  12. Lollipop
  13. Marshmallow

What are the advantages of android?

  • Open Source Operating System.
  • Easy to customize android platform.
  • A wide range of mobile applications available on google play store for end users.
  • Provides support for Messaging, Web Browsing, Data Storage, Calling, Connectivity(GSM, CDMA, Blue Tooth, Wi-Fi etc.), Media etc.

What are the basic tools used to develop an android app?

  • JDK
  • Eclipse+ADT plugin or Android Studio
  • SDK Tools

what was the first mobile phone with android Operating System?

Google announces the development of an android operating system in 2007. HTC launched the first android mobile (T-Mobile G1) in 2008.

Tell names of android devices which are using Android OS?

  • Smart Phones
  • Tablets
  • Smart TVS
  • Cars
  • Goolge Glass
  • Smart Watches

Top/Best Android Developer Interview Preparation Questions and Answers for Freshers/Beginners 2016

What are the core building blocks of android?

Android core building blocks or Android basic components like  Activity, View, Intent, AndroidMainifest.XML, Broadcast Receiver, Content Provider, Services and Fragment are basic parts of any android application. Before making any android app we must understand all of these android core building blocks.

1. Android core building blocks that must have in Android App

  • Activities
  • Views
  • AndroidMainifest.XML
  • Intents

2. Android core building blocks that can have in Android App

  • Services
  • Fragments
  • Content Providers
  • Broadcast Receivers

Detail Explanation- Click Here

Define Android Architecture?

Android Architecture– If you are the normal Android user, you may be know how to use basic features like calling, messaging, internet surfing, photo capturing etc. But when you want to become Android developer then these information is not enough. We should know all the key concepts of Android Operating System. Here I will explain the Android architecture in details.

Android Architecture or Android Software Stack is categorized into five parts:

  • Linux kernel
  • Native libraries (middleware)
  • Android Runtime
  • Application Framework
  • Applications

Detail Explanation- Click Here

What is the APK Format?

The Android packaging key is compressed with Classes,UI Components, Resources, Assets and manifest. All files are compressed to a single file is called APK.

What is an Activity?

Activity is a class of android library which represents single screen and it is most important part of android core building blocks. Every android app should have at least one activity. Activity has always User Interface. When you open any android app and you will see one screen it’s an activity, we can call it launcher or main activity.

What is an Intent?

Intents are used for moving between android core building blocks or components (Like Activity, broadcast Receiver and Services). It’s mostly used for launching activity and passing data between activities.

What is an Explicit Intent?

Explicit Intent adds the destination component’s location. In such case, intent provides the external class to be invoked.

What is an Implicit Intent?

Implicit Intent doesn’t add the destination component’s location. In such case, intent provides information of available components provided by the system that is to be invoked.

How to pass data between two Activities?

Intent intentInstance = new Intent(getApplicationContext(), ActivityTwo.class); 
startActivity(intentInstance);

What is Content Provider?

Content Provider Component is used to transfer the information from one app to another app within the device

What is Fragment?

Fragments are like parts of activity. An activity can display one or more fragments on the screen at the same time.

What is Broadcast Receiver?

Broadcast Receiver is allowed to register system or application events. All registered receivers for an event are notified by the Android run time once this event happens. For Example we get alert about “Low Batter Alert”, system continuous check the battery status when it reaches to 15% it shows pop up for low battery.

What is AndroidMainifest.xml file?

It contains information about all components like activities, content providers, android broadcast receivers, android services, user permissions etc. It is like the web.xml file in Java EE.

What is AAPT?

AAPT is an acronym for android asset packaging tool. It handles the packaging process.

What is ANR?

ANR stands for Application Not Responding. It is a dialog box that appears if the application is no longer responding.

What is NDK?

NDK stands for Native Development Kit. By using NDK, you can develop a part of app using native language such as C/C++ to boost the performance.

What is ADB?

ADB stands for Android Debug Bridge. It is a command line tool that is used to communicate with the emulator instance.

What is a portable wi-fi hotspot?

The portable wi-fi hotspot is used to share internet connection to other wireless devices.

What is Android UI Widgets?

Android UI Components/Widgets

  • Android ProgressDialog & ProgressBar
  • Android Button
  • Android TextView
  • Android ImageView
  • Android CheckBox
  • Android RadioButton
  • Android Spinner & Custom Spinner
  • Android AlertDialog & Custom AlertDialog
  • Android Analog & Digital Clock
  • Android TimePicker
  • Android DatePicker
  • Android RatingBar
  • Android Switch
  • Android ToggleButton
  • Android Seekbar

Name the dialog box which are supported by android?

  • AlertDialog,
  • ProgressDialog,
  • DatePickerDialog,
  • TimePickerDialog

Name some exceptions in android?

  • NullPointerException
  • ArithmeticException
  • InflateException
  • Surface.OutOfResourceException
  • SurfaceHolder.BadSurfaceTypeException
  • WindowManager.BadTokenException

What is the name of the database used in android?

SQLite: An opensource and lightweight relational database for mobile devices.

What is service in android?

A service is a component that runs in the background. It is used to play music, handle network transaction etc.

What language does android support to develop an application?

Android applications has written using the java(Android SDK), C# for Xamarin and C/C++(Android NDK).

What is View and ViewGroup in Android?

View group ( invisible container that contains views are called View group)

View- All UI Components called view i.e TextView, IamgeView, EditText etc.

What is share preference in Android?

Shared preferences are very useful and  simplest way to store the data in XML documents.

What kind of layouts available in Android?

Android Layouts

  • Android LinearLayout
  • Android RelativeLayout
  • Android FrameLayout
  • Android TableLayout
  • Android ListView
  • Android GridView

What are the different storages available in android?

Shared Preferences

Internal Storage

External Storage,

SQLite Databases

Network Connection via web services

What is WebView in Android?

WebView is a kind of view that will  display web pages inside your android application.

What is singleton class in android?

Singleton is a class which can create only an object,and allow to share share able to all other classes.

What is drawable folder in android?

A compiled visual resource that can used as a backgrounds,banners, icons,splash screen etc.

Top/Best Android Developer Interview Preparation Questions and Answers for Experienced or 1/2 year experience senior developer 2016

What happen if we put Toast in doinbackground() method of AsyncTask ?

It will thow Runtime exception. The code in the doInBackground() method runs on its own thread so you cannot access any UI element from there directly as they are running on the UI thread.

So you got two options.

  1. You handle all the UI stuff in the onPreExecute() and onPostExecute() method which run on the UI thread.
  2. You handle UI stuff in the onProgressUpdate() method which also runs on the UI thread. You can trigger this method from within doInBackground() by calling publishProgress().

How to increase heap size memory of app?
add following line in application of AndroidMainifest.xml file

<application android:allowBackup="true" ... ... >

What will happen if we put intent filter in more than one activity in AndroidMainifest.xml file?

if we put intent filter in two activity then it will generate two separate icon for both activity on android home screen
For example

<activity android:name=".activity.SplashActivity" android:screenOrientation="portrait" >
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

</pre>
<pre><activity android:name=".activity.MainActivity" android:screenOrientation="portrait" >
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

here we add intent filter in MainActivity and SplashActivity, hence it will generate two icons for both activity and we can open these activities separately from their icons.

What is Android Material Design Support Library?

Material Design Support library is best solution for implementing material design features in your android application.

compile 'com.android.support:design:23.1.0'

How to make pixel perfect design and support all devices?

you have to make separate drawable for all screen resolutions

  • for supporting normal devices
    make dimensions in values/dimen.xml file
  • for supporting 7 inch devices like tablets
    make dimensions in values-sw600dp/dimen.xml file
  • for supporting 10 inch devices like tablets
    make dimensions in values-sw720dp/dimen.xml file

What is JSON Web Service?

JSON- Java Script Object Notation
JSON is very famous parsing for web services

Symbols use in JSON format

[ ] — Indicate array

{ } — Indicate object

Sample Format

{  
   "List":[  
      {  
         "Id":"1",
         "Name":"Android Tutorial"
      },
      {  
         "Id":"1",
         "Name":"Android Development Interview Questions adn Answers"
      }
   ]
}

here, list indicates array and it has many objects with id and name filed.

 

Useful Resources for Android Application Development

Android Asset Studio– Useful to make drawable images for different types screens resolutions

Flat Icon– Easy to find free useful icons

Material Palette– Useful to get idea for choosing colors for material design

Android Arsenal– Largest collection of android useful libraries

Android Developer Blog– Get the latest news in android world

Pixel To DP Converter– Useful to convert from pixel to DP and vice versa.

 

Friends these all are questions which may be faced during your next android interview. if you have any new interesting question then share your comments bellow.

nirav kalola