Android interview questions

Android interview questions

In the year 2008 Android came as a popular computing platform, which is based on the Linux operating system. In the smartphone market, it became one of the most leading names that managed to change the whole. In the last ten years time, it grabs the majority of market share sharing with iOS and has effectively become the world most popular operating system. With the maturity of Android, it is finding its new way into a variety of devices, not just on smartphones but also includes televisions, projectors, automobiles and even now the vehicles.

Today with the advent of the Android platform, the Android developers are huge in demand and every sector and industry is looking to recruit them in-house. If you aspire to be an Android developer, then this is just the place for you. Given below is the list of questions, which answers both basic and advanced concepts of Android. These questions if well prepared before an interview shall give an extra edge to the candidate and give confidence of facing the panel:

Below is the list of 40+ Android Interview Questions with answers

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Android interview questions

In a general term, the container means some object that can be used to hold or to procure. In a similar manner here, containers are used to hold objects and the widgets altogether.It depends on which specific item is it required and what kind of arrangement is needed. It can be used to hold labels, fields or buttons.

Dalvik plays an important role in the development of Android. It acts as a virtual machine where the Android application runs. It is with the help of Dalvik only that devices can execute multiple virtual machines effectively along with better memory management.

Follow the below steps to create a bounded service through AIDL

  • Step 1. Create the .aidl file that defines the programming interface.
  • Step 2. Implement the interface, by extending the inner abstract stub class and imparting its methods.
  • Step 3. Expose the interface by implementing the service to the users.

Default resources contain the default string and files. If this resource is not present the error will keep occurring, and the app will not be able to run. Resources are placed in subdirectories under the project res/ directory. Moreover, therefore helps the app to function in the desired conditions.

Fragments are reusable in nature and is a portion of an activity. In other words, it is modular that can be combined or is movable in an activity.

Terminating or killing the foreground activity is the last and final savior. It is generally desirable or is the best time to kill this activity when it is consuming too much of memory. When the memory paging state is reached by the activity, it is killed so that the interface can sustain the responsiveness of the user of the application.

It is broadcast from sendstickybroadcasr() method. This allows the intent to float even after the broadcast and allowing others to collect data from.

The supporting facility of Android new version depends on the capabilities and specs of the phone. There are few Android power phones that allow the user to update their version to the higher operating version. Few don’t allow getting the updated version work. Either the new feature will not be supported, or the performance of the operating device will slow down.

In the latest update of Android version 6.0, the official Android code name is known as a marshmallow. It was launched in May 2015. This was the successor of the Android version 5.0 named as Lollipop. Google named this version as a marshmallow on 17th August 2015 for Nexus devices.

Every application should have an Androidmanifest.xml file at the root of the project source set. This file describes the essential information required by the user for the app to the Android build tools. Apart from this, it is required for the following reasons:

  • To give permission that the application requires to ensure the access is protected.
  • To provide with the hardware and software features, which the app requires when installing from Google play etc.

It is an instruction for Android OS that specifies how the activity should be launched or performed. The activities are performed into two areas, which are:

  • Tasks: It’s a collection of activities, with which the users interact when they perform certain jobs. An application contains a number of activities.
  • Back Stack: Back stack in a back stack the activities are arranged with the order in which each is opened. This maintained stack called back stack.

Sticky intent sticks with the Android for future broadcast listeners. For instance, if Battery low event occurs then that intent will be stick with Android, so that if any future user requested for Battery – Low, it will be fired.

Serializable is a standard Java interface. It is not a part of the Android SDK. Its simplicity is its biggest beauty. Just by implementing this interface the POJO will be ready to jump from one particular activity to another. There is another interface known as parseable. It is a part of the Android SDK. Paracelable was specifically designed in a way that there is no reflection left while using.

The architecture of Android application has few components, which have their functions to perform:

  • Service: It performs the background functions
  • Intent: Performs the interconnection function between activities and data passing mechanism
  • Resource: Externalization it is used to perform strings and graphics functions
  • Notification: This shows the lights, sound, icon, notification, incoming chats messages dialogue box, etc.
  • Content providers: It shares the data between applications.