Android Interview Questions
1.Who is the founder of Android?
Andy Rubin
2.What is Android?
Android is an open-source, Linux-based operating system used in mobiles, tablets, television.
3.What is the Android Architecture?
It includes your operating system, middleware, and important applications. Each layer int the architecture provides different services to the layer.
There are:
1.Linux kernel
2.Libraries
3.Android Framework
4.Android Applications.
4.Explain Android Application Architecture?
Android application architecture:
1.Services perform background functionalities.
2.Intent will perform the inter connection between activities and the data passing mechanism.
3.Resource Externalization strings and graphics.
4.Notification light, sounds, icon, Notification, Dialog box and toast.
5.Content Providers will share the date between applications.
5.What data types are supported by AIDL?
1.string
2.charSequence
3.List
4.Map
5.all native Java data types like int,long,char and boolean
6.Does android support other languages than java?
1.Kotlin
2.C/C++
3.Xamarin(C#)
4.BASIC
5.Corona(LUA)
6.PhoneGap/cordova (CSS3,HTML5, and JavaScript)
7.Rhodes(Ruby)
8.Scala.
7.What is activity in Android?
Activity is a frame or window in java that represents GUI. It represents one screen of android.
Activity performs actions on the screen. If you want to do any operations, we can do activities.
8.Life cycle methods of android activity?
There are 7 life-cycle methods of activity.
1.onCreate()
2.onStart()
3.onResume()
4.onPause()
5.onStop()
6.onRestart()
7.onDestroy()
9.What is an Intent?
It is connected to either the external world of application or internal world of application, Such as, opening a pdf is an Intent and connects to the web browser.
10.What is a service in android?
The service is like an activity to do background functionalities without UI interaction.
11.Explain the use of 'bundle' in android?
We use bundles to pass the required data to various subfolders.
12.What are layouts placed in Android?
placed in the layout folder.
13.What is a fragment?
The fragment is a part of activity by which we can display multiple screens on 1 activity.
14.What is the adapter in Android?
An adapter is used to create a child view to present the present view items.
15.what is sleep mode in Android?
In sleep mode, CPU is slept and does not accept any commands from android device except Radio interface layer and alarm.
16.What is container in android?
The container holds objects,widgets,labels,fields,icon,buttons.
17.what is ADB in android?
It acts as a bridge between emulator and IDE, it executes remote shell commands to run applications on an emulator.
18.What is the order of dialog-box in android?
Positive, Neutral,Negative.
19.Name the dialog box which is supported by Android?
1.Alert dialog
2.Progress dialog
3.Date Picker dialog
4.Time picker dialog
20.What are the some exceptions in Android?
1.Inflate Exception
2.Surface.OutOfResourceException
3.SurfaceHolder.BadSurfaceTypeException
4.WindowManager.BadTokenException
21.How to launch an activity in android?
Using with intent
Intent intent = new Intent(this, MyTestActivity.class);
startActivity(intent);
22.What is singleton class in android?
A class which can create only an object, that object can be shared to all other classes.
23.What are the different states wherein a process is based?
There are 4 possible states:
1.foreground activity
2.visible activity
3.background activity
4.empty process
24.which kernel is used in android?
Android is customized Linux 3.6 kernel.
25.What folders are impotent in android project?
androidManifest.xml
build.xml
bin/
src/
res/
assets/
26.How do you find any view element into your program?
Using with findViewById we can find view element.
27.what is drawable folder in android?
A compiled visual resourse that can used as a backgrounds,banners,icons,splash screen etc.