Android Interview Questions

Android Ecosystem

What is Anroid

• It is developed by google.

What is DVM

• Dalvik Virutal Machine >> an android virtual machine optimized for mobile device.

What is the difference between DVM & JVM

• JVM is Heaviside

What is the architect consist

• Linux kernel
• Libraires
• Android Application
• Android Framework

Component

• Android Context

• Activity Manager

• Window Manager

• Content Provider

• Camera

• Email

• Calendar

Which are main componant

• Activities
• Services
• Broadcast
• Content Provider

Asset packaging Tool

• Zip jar file or APK

What is AVD (Android virtual Device)

• Hardware
• Storage Area
• Screen

What is APK (Android Application Package)

• apk file genrate to load on app strore

Android Context

• A abstract class whose implementation provided by android system. It gives the context of the current state of the application or object.

Can be invoked via:

• getApplicationContext()
• getContext()
• getBaseContext()
• this (Current instance or reference)

Android Application

Application which on Android environment

NDK (Native Development Kit)

ANR (Android app not responding)

What is API Level

• An integer number indicating the corresponding Android framework; It shows to the programmer what functionalities may be included when designing the application.

Diffrence

• VersionCode for developer
• Versionname identification
• all the electronic device which support Android hardware configurations

##Intent

• An object you can use to request an action from another app component (such as Activities, Services, Broadcast, Receivers, and Content Providers).

• to start the service

• to broadcast the service

intent type

• implicit -
• explicit -

Intetn Information

• Name
• String
• URI
• Category
• Flag - Extra instructions to the Android System

Multitask

• Chooser Dialog

Intent-Filter

• An expression in app's manifest file that specifies the type of intents the component would like to receive.

• Each intent filter specifies the type of intents it accepts based on intent's

• action

• data

• Category

What is pending intent

• As object that wraps another intent
• A token that you give to a foreign application which allows the foreign application to use your application's permission
• By giving a Pending Intent to another application, you grant it the right to perform the operation you have specified as if the other application was yours initial one

Intent resolution

sticky intent

• It sticks with android for future broadcast listeners

Manifest file

• Exactly one - Exception is the case when a 3rd party library is added. Then the library has a manifest itself as well
• Application Name - it serves as a unique identifier of the application
• Activities
• Services
• Broadcaster
• Content Provider
• Permission - By default application is allowed to perform any operations that would adversely impact other applications, the operating system, or the user.