Android programming is growing day by day. The questions asked by interviewers in android is given below. A list of top android interview questions and answers:
1. What is Android?
Android is an open-source, Linux-based operating system used in mobiles, tablets, televisions, etc.
2. Who is the founder of Android?
Andy Rubin.
3. Explain the Android application architecture.
Following is a list of components of Android application architecture:
Services: Used to perform background functionalities.
Intent: Used to perform the interconnection between activities and the data passing mechanism. Resource Externalization: strings and graphics.
Notification: light, sound, icon, notification, dialog box and toast.
Content Providers: It will share the data between applications.
4. What are the code names of android?
- Aestro
- Blender
- Cupcake
- Donut
- Eclair
- Froyo
- Gingerbread
- Honeycomb
- Ice Cream
- Sandwich
- Jelly
- Bean
- KitKat
- Lollipop Marshmallow
5. What are the advantages of Android?
Open-source: It means no license, 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 a highly optimized virtual machine for mobile devices, called DVM (Dalvik Virtual Machine).
6. Does android support other languages than java?
Yes, an android app can be developed in C/C++ also using android NDK (Native Development Kit). It makes performance faster. It should be used with the Android SDK.
7. What are the core building blocks of android?
The core building blocks of Android are
Activity
View
Intent
Service
Content Provider
Fragment etc.
8. What is activity in Android?
Activity is like a frame or window in java that represents GUI. It represents one screen of android.
9. What are the life cycle methods of android activity?
There are 7 life-cycle methods of activity. They are as follows:
onCreate()
onStart()
onResume()
onPause()
onStop()
onRestart()
onDestroy()
10. What is the intent?
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 an email, etc. There are two types of intents in android:
Implicit Intent
Explicit Intent
11. How are the view elements identified in the android program?
View elements can be identified using the keyword findViewById.
12. Define Android toast.
An android toast provides feedback to the users about the operation being performed by them. It displays the message regarding the status of the operation initiated by the user.
13. Explain the use of 'bundle' in android?
We use bundles to pass the required data to various subfolders.
14. What is an application resource file?
The files which can be injected for the building up of a process are called an application resource file.
15. List the various storages that are provided by Android.
The various storage provided by android are:
Shared Preferences
Internal Storage
External Storage
SQLite Databases
Network Connection
16. How are layouts placed in Android?
Layouts in Android are placed as XML files.
17. What is the implicit intent in android?
The Implicit intent is used to invoke the system components.
18. What is explicit intent in android?
An explicit intent is used to invoke the activity class.
19. What is a fragment?
The fragment is a part of Activity by which we can display multiple screens on one activity.
20. Which types of flags are used to run an application on Android?
Following are two types of flags to run an application in Android:
FLAG_ACTIVITY_NEW_TASK
FLAG_ACTIVITY_CLEAR_TOP