Q.1 what is Android?
Answer- Android is an open source operating
system. Which is specially developed for mobile devices like mobile phones,
tablets etc. Android is built upon Linux Kernel. Android is developed by
Google.
Q.2 when was android beta version was
released?
Answer- In November, 2007
Q.3 when android 1.0 version was
released?
Answer- In 2008
Q.4 which features was not supported by
android 1.0?
Answer- Soft Keyboard
Q.5 which android version was released
only for tablets?
Answer- Android 3.0 – (Honeycomb)
Q.6 which toolset is required to write
and test an android application on android enabled devices?
Answer- Google Android SDK (Software
Development Kit)
Q.7 what is the latest released version
of android?
Answer- Android 5.0 – (Lollipop)
Q.8 what are the code names for all
android versions?
Answer-
VERSION
|
CODE NAME
|
1.5
|
Cupcake
|
1.6
|
Donut
|
2.0-2.1
|
Éclair
|
2.2
|
Froyo
|
2.3 - 2.3.2
2.3.3 - 2.3.7
|
Ginderbread
|
3.0
3.1
3.2
|
Honeycomb
|
4.0 – 4.0.2
4.0.3 – 4.0.4
|
Ice Cream Sandwich
|
4.1
4.2
4.3
|
Jelly Bean
|
4.4
|
Kitkat
|
5.0
|
Lollypop
|
Q.9 when first version of android OS was
released?
Answer- In 2008
Q.10 what is android architecture?
Answer- There is 5 main blocks of the
android architecture –
Android Application/JAVA Application
|
Java API
|
Dalvik Java Virtual Machine (DVM)
|
Native C/C++ libraries
|
Device Drivers/Linux Kernel
|
Q.11 what is the responsibilities of
Linux Kernel/Device Drivers?
Answer- Linux Kernel is responsible for
OS functions such as-
1.
Processor
Management
2.
Memory
Management
3.
File
Management
4.
Power
Management
Device Drivers
are –
1.
Display
Driver
2.
Camera
Driver
3.
Keypad
Driver etc.
Q.12 why dalvik virtual machine (DVM)
was developed?
Answer- DVM was developed by Google. It
was developed to optimize the performance of Java applications on mobile
devices with limited capabilities.
Q.13 how DVM optimize the performance?
Answer- DVM takes the .class and
combines them into one or more Dalvik Executable “.dex” files by removing duplicate
information among the java classes and reduces the resultant file size compared
to JAR file.
Q.14 which language is used to write
android application?
Answer- Java Language
Q.15 what are the application components
in android?
Answer- there is 4 application
components in android-
1.
Activity
2.
Services
3.
Content
providers
4.
Broadcast
Receivers
Q.16 what is the importance of having an
emulator within the android environment?
Answer- Emulator is a safe place for
testing codes especially if it is in the early design phase.
Q.17 what are the android activity life
cycle methods?
Answer- there are 7 callback/events/methods
in android activity life cycle. They are as follow-
1.
onCreate()
–this is the first callback and called when the activity is first created.
2.
onStart()
- this callback is called when the activity becomes visible to the user.
3.
onResume()
– this is called when the user starts interacting with the application.
4.
onPause()
– the pause activity does not receive user input and cannot execute any code
and called when the current activity is being paused and the previous activity
is being resumed.
5.
onStop()
– this callback is called when the activity is no longer visible.
6.
onDestroy()
– this callback is called before the activity is destroyed by the system.
7.
onRestart()
– this callback is called when the activity restarts after stopping it.
Q.18 what are the activity states in
android?
Answer- there are 4 activity states are
available in android-
1.
Activity/Running
state – this is a state when an activity is in front and has focus on it. It is
completely visible and active to the user.
2.
Paused
state – In pause state , the activity is partially visible to the user but not
active and lost focus.
3.
Stopped
state – This is when the activity is no longer visible on the screen.
4.
Destroyed/Dead
state – When it is no longer exists in the memory.
Q.19 what are activity lifecycle loops?
Answer- there are three activity life
cycle loops exist for every activity in android-
1.
Entire
Lifecycle – Lifetime between the first call to the onCreate() and the final
call to onDestroy() method is known as Entire Lifecycle.
2.
Visible
Lifecycle – Lifetime between onStart() and onStop() methods calls is known as
Visible Lifecycle.
3.
Foreground
Lifetime – Lifetime between onResume() to onPause() method calls is known as
Foreground Lifecycle.
Q.20 who is the founder of android?
Answer- Andy Rubin
Q.21 does android support languages
other than java?
Answer- Yes. C and C++ as native
languages to increase the performance.
Q.22 what is service?
Answer- This is a component that runs in
the background to perform long running operations without interaction with
user. Like play music in background, fetching data over the network etc.
Q.23 states of service?
Answer-
1.
Started
2.
Bound
Q.24 callbacks of service?
Answer-
1.
onStartCommand()
2.
onBind()
3.
onUnbind()
4.
onRebind()
5.
onCreate()
6.
onDestroy()
Q.25 what is broadcast receiver?
Answer- Broadcast receiver simply
responds to broadcast messages from
other application
or from the system itself.
Q.26 what is content provider?
Answer- a content provider supplies data
from one application to others on request.
Q.27 what is the name of database used
in android?
Answer- SQLite- an opensource and
lightweight database
Q.28 what is intent?
Answer- intent is a kind of message
which passed to components, used to launch an activity, send a message, send an
email etc. two type of intents are available in android-
1.
implicit
intent- used to invoke activity class
2.
explicit
intent- used to invoke system components
Q.29 how to call another activity in
android?
Answer- by using explicit intent
Intent
i=new Intent(getApplicationContext(),calledActivityname.class);
startActivity(i);
Q.30 what are the different storage
methods in android?
Answer-
1.
shared
preference
2.
internal
storage
3.
external
storage
4.
SQLite
database
Q.31 what is ANR?
Answer- ANS is acronym for Application
Not Responding. Android system shows this dialog if application has been unresponsive
for a long time period.
Q.32 what is NDK?
Answer- NDK is acronym for Native
Development Kit which is used to develop a part of android application with the
native language like c and c++ for optimize the performance of application.
Q.33 what is ADB?
Answer- ADB is acronym for Android Debug
Bridge. A command line tool used to communicate with emulator instantly.
Q.34 what is AAPT?
Answer- AAPT is acronym for Android
Asset packaging Tool. A tool who provides ability to deal with zip compatible archives,
which include creating, extracting as well as viewing its contents.
Q.35 what is fragment?
Answer- fragment is a part of an
activity. Used to display multiple screen on a single activity.
Q.36 what is activity creator?
Answer- It is first step towards to
create a new android project. It is made up of a shell script that will used to
create new file system structure necessary for writing codes within the android
IDE.
Q.37 when the onStop() method invokes?
Answer- when an activity is no longer
visible to the user.
Q.38 what is the AndroidMenifest.xml?
Answer- An essential
XML file declared in root directory in every android application. It contains
the information about the application that android system must know before the
code can be executed
Q.39 when we celebrate birthday of android?
Answer- On 5th November.
Please update this. The latest Android version is Marshmallow (6.0).
ReplyDeleteHello Alnel Vincent. Thank you for your feedback. I will definitely update it soon. I am sorry I was busy recently. Keep me update if any changes required.
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