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Android Application Development Interview Questions

Our experts providing  Android Application Development  interview questions & Answers/Faqs can develop your carrier & knowledge to find the right job in a good MNC’s, doesn’t matter what kind of company you’re hired.

1) What is Android?

Answer: It is an open-sourced operating system that is used primarily on mobile devices, such as cell phones and tablets. It is a Linux kernel-based system that’s been equipped with rich components that allows developers to create and run apps that can perform both basic and advanced functions.

2) What is the Android Architecture?

Answer: Android Architecture is made up of 4 key components:
– Linux Kernel
– Libraries
– Android Framework
– Android Applications

3) Describe the Android Framework.

Answer: The Android Framework is an important aspect of the Android Architecture. Here you can find all the classes and methods that developers would need in order to write applications on the Android environment.

4) What are the code names of android?

Answer:
Aestro
Blender
Cupcake
Donut
Eclair
Froyo
Gingerbread
Honycomb
Ice Cream Sandwitch
Jelly Bean
Kitkat
Lollipop
Marshmallow

5) What are the advantages of android?

Answer: Open-source: It means no licence, distribution and development fee.

Platform-independent: It supports windows, mac and linux platforms.

Supports various technologies: It supports camera, bluetooth, wifi, speech, EDGE etc. technologies.

Highly optimized Virtual Machine: Android uses highly optimized virtual machine for mobile devices, called DVM (Dalvik Virtual Machine).

6) Does android support other language than java?

Answer: Yes, android app can be developed in C/C++ also using android NDK (Native Development Kit). It makes the performance faster. It should be used with android SDK.

7) Differentiate Activities from Services.

Answer: Activities can be closed, or terminated anytime the user wishes. On the other hand, services are designed to run behind the scenes, and can act independently. Most services run continuously, regardless of whether there are certain or no activities being executed.

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

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

9) What are the core building blocks of android?

Answer: The core building blocks of android are:

Activity
View
Intent
Service
Content Provider
Fragment etc.

10) What is activity?

Answer: Activity is like a frame or window in java that represents GUI. It represents one screen of android.

11) When is the onStop() method invoked?

Answer: A call to onStop method happens when an activity is no longer visible to the user, either because another activity has taken over or if in front of that activity.

12) How can the ANR be prevented?

Answer: One technique that prevents the Android system from concluding a code that has been responsive for a long period of time is to create a child thread. Within the child thread, most of the actual workings of the codes can be placed, so that the main thread runs with minimal periods of unresponsive times.

13) What role does Dalvik play in Android development?

Answer: Dalvik serves as a virtual machine, and it is where every Android application runs. Through Dalvik, a device is able to execute multiple virtual machines efficiently through better memory management.

14) What is the AndroidManifest.xml?

Answer: This file is essential in every application. It is declared in the root directory and contains information about the application that the Android system must know before the codes can be executed.

15) What are the life cycle methods of android activity?

Answer: There are 7 life-cycle methods of activity. They are as follows:

onCreate()
onStart()
onResume()
onPause()
onStop()
onRestart()
onDestroy()

16) What is intent?

Answer: It is a kind of message or information that is passed to the components. It is used to launch an activity, display a web page, send sms, send email etc. There are two types of intents in android:

Implicit Intent
Explicit Intent

17) What is implicit intent in android?

Ans: Implicit intent is used to invoke the system components.

18) What is explicit intent in android?

Ans: Explicit intent is used to invoke the activity class.

19) What is service in android?

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

20) Which types of flags are used to run an application on Android?

Ans: Following are two types of flags to run an application in Android:

FLAG_ACTIVITY_NEW_TASK
FLAG_ACTIVITY_CLEAR_TOP………..For more Click Here

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