Android Interview Preparation

Dear learner, todays world is very fast and furious. So, if you want to establish your career here, you have to prepare yourself fast and furiously. Otherwise, you will lose your perfect value of success. Please read everything carefully and do practice more and more. You should know, "PRACTICE MAKES A MAN PERFECT".

Android Question: What is Android?

Android Answer: Android is a stack of software for mobile devices which includes an Operating System, middleware 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.

 

Android Question: What is an Activity?

Android Answer: A single screen in an application, with supporting Java code.

 

Android Question: What is an Intent?

Android Answer: A class (Intent) which 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).

 

Android Question: What is a Sticky Intent?

Android Answer: 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.

 

Android Question: How the nine-patch Image different from a regular bitmap? Alternatively, what is the difference between nine-patch Image vs regular Bitmap Image?

Android Answer: It is one of a resizable bitmap resource which is being used as backgrounds or other images on the device. The NinePatch class allows drawing a bitmap in nine sections. The four corners are unscaled; the middle of the image is scaled in both axes, the four edges are scaled into one axis.

 

Android Question: What is a resource?

Android Answer: A user defined JSON, XML, bitmap, or other file, injected into the application build process, which can later be loaded from code.

 

Android Question: How will you record a phone call in Android? 

OR

How to handle an Audio Stream for a call in Android?

Android Answer: Permission.PROCESS_OUTGOING_CALLS: Will Allow an application to monitor, modify, or abort outgoing calls. So using that permission we can monitor the Phone calls.

 

Android Question: Does Android support the Bluetooth serial port profile?

Android Answer: Yes.

 

Android Question: Can an application be started on powerup?

Android Answer: Yes.

 

Android Question: What is the APK format?

Android Answer: The APK file is compressed AndroidManifest.xml file with extension .apk. It also includes the application code (.dex files), resource files, and other files which are compressed into a single .apk file.

 

Android Question: How to Translate in Android?

Android Answer: The Google translator translates the data of one language into another language by using XMPP to transmit data. You can type the message in English and select the language which is understood by the citizens of the country in order to reach the message to the citizens.

 

Android Question: Describe Briefly the Android Application Architecture

Android Answer: Android Application Architecture has the following components:

    Services like Network Operation
    Intent – To perform inter-communication between activities or services
    Resource Externalization – such as strings and graphics
    Notification signaling users – light, sound, icon, notification, dialog etc.
    Content Providers – They share data between applications

 

 Android Question: What is needed to make a multiple choice list with a custom view for each row?

Android Answer: Multiple choice list can be viewed by making the CheckBox android:id value be “@android:id /text1″. That is the ID used by Android for the CheckedTextView in simple_list_item_multiple_choice.

 

 Android Question: What dialog boxes are supported in android?

Android Answer: Android supports 4 dialog boxes:

AlertDialog: An alert dialog box supports 0 to 3 buttons and a list of selectable elements, including check boxes and radio buttons. Among the other dialog boxes, the most suggested dialog box is the alert dialog box.

ProgressDialog: This dialog box displays a progress wheel or a progress bar. It is an extension of AlertDialog and supports adding buttons.

DatePickerDialog: This dialog box is used for selecting a date by the user.

TimePickerDialog: This dialog box is used for selecting time by the user.