TOP Android Interview Questions and Answers
What is Android?
Android is a stack of software for mobile devices which has Operating System, middle-ware and some key applications. The application executes within its own process and its own instance of Dalvik Virtual Machine. Many Virtual Machines run efficiently by a DVM device. DVM executes Java languages byte code which later transforms into .dex format files.
What is activity?
A single screen application with supporting Java code
What is intent in Android?
A class (Intent) will describes what a caller desires to do. The caller will send this intent to Android’s intent resolver, which finds the most suitable activity for the intent. E.g. opening a PDF document is an intent, and the Adobe Reader apps will be the perfect activity for that intent class).
What is a Sticky Intent?
sendStickyBroadcast() performs a sendBroadcast (Intent) known as sticky, i.e. the Intent you are sending stays around after the broadcast is complete, so that others can quickly retrieve that data through the return value of registerReceiver (BroadcastReceiver, IntentFilter). In all other ways, this behaves the same as sendBroadcast(Intent)
One example of a sticky broadcast sent via the operating system is ACTION_BATTERY_CHANGED. When you call registerReceiver() for that action — even with a null BroadcastReceiver — you get the Intent that was last broadcast for that action. Hence, you can use this to find the state of the battery without necessarily registering for all future state changes in the battery.
What Programming languages does Android support for application development?
Android applications support using Java programming Language. which is coded in Java and complied using Android SDK.
What is a resource?
A user defined JSON, XML, bitmap, or other file, injected into the application build process, which can later be loaded from code.
How will you record a iphone call in Android? or How to handle on Audio Stream for a call in Android?
PermissionsWOCESS_OUTGOING_CALLS: Will Allows an application to monitor, modify, or abort outgoing calls. So through that we can monitor the Phone calls
What’s the difference between class, file and activity in android?
Class – The Class file is complied from .java file. Android will use this .class file to produce the executable apk
File – It is a block of resources, arbitrary information. It can be an y file type.
Activity – An activity is the equivalent of a Frame/Window in GUI tool kits. It is not a file or a file type it is just a class that can be extended in Android for loading UI elements on view.
Does Android support the Bluetooth serial port profile?
Yes, Android support the Bluetooth serial port profile
Can an application be started on power up?
Yes, application can be started on power up.