Android interview questions

Following are the code names with year:

1. Astro
2. Blender
3. Cupcake (April 2009)
4. Doughnut (September 2009)
5. Eclair (October 2009)
6. Froyo (may 2010)
7. Gingerbread (December 2010)
8. Honeycomb (February 2011)
9. Ice Cream Sandwich (October 2011)
10. Jellybean (July 2012)
11. Kitkat (October 2013)
12. Lollipop (November 2014)
13. Marshmallow (since October 2015)

Advantages of Android are as follows:

• It is an Open source that requires no licensing
• It is Platform independent that supports Windows, Mac, and Linux platforms.
• Supports different technologies like camera, Bluetooth, wifi, speech, EDGE, etc.
• It is a highly optimized virtual machine.

Android supports C++, C. The app can be developed in C or C++ using Android NDK (Native development kit). This makes system works faster.

There are seven lifecycle methods of Android activities. They are:

• On create()
• On start()
• On resume()
• On pause()
• On stop()
• On restart()
• On destroy()

DDMS is Dalvik Debug Monitor Server.This gives a wide array of debugging features of which are

• Port forwarding services
• Screen capture
• Thread and heap information
• Network traffic tracking
• Location data
• spoofing

Dialogue box supported by Android are:

• Alert dialogue
• Process dialogue
• Data picker dialogue
• Time picker dialogue

These are the following exceptions in Android:

• Inflate exception
• Surface.out of resource exception
• Surface holder bad surface type exception
• Window manager took exception.

Tools used to develop an Android app are as follows:

• JDK
• Eclipse +ADT Plugin
• SDK Tools

The Google Android SDK is a set of tools that are used by the developers to write the app on Android-enabled devices. It contains a graphical interface that emulates an Android-driven handheld environment and allows the developers to debug their codes as per the requirements.

A nine- patch image allows the resizing of the image that can be used as background or other image size requirements for the target device. The nine- patch refers to the way one can resize the image. It can be done in the in the following manners

• 4-image corner unscaled one.
• Four edges, scaled in 1 axis
• The last middle one that can be scaled into both the axes.

Portable Wi-Fi hotspot allows the users to share a mobile Internet connection with another device. Using an Android powered phone as a Wi-Fi hotspot user can use their laptop to connect to the Internet using the same access point.

XML based layouts provide a consistent and standard means of setting GUI format. In general use, layout details are placed in XML files, and all other items are generally placed in a source files.

Orientation is set using set orientation (), dictates whether the linear layout is represented as a row or else as a column. There the values are set as HORIZONTAL or VERTICAL.

Activities can be closed or can be terminated easily as and when the user wants to. Services are designed to run on the background or behind the scenes and can act independently. Most of the services run on a continuous basis regardless of their certain or no certain activities been executed.

The emulator lets the developers “play” all around the interface that gives the experience of an actual mobile device. It is for writing and testing codes, and debug too. Emulators are safe for testing codes especially if the user is in the early stage of design.