Android

ANDROID BASICS PART II ANDROID BASICS PART III

ANDROID BASICS PART I

Mohan Lalwani

lalwanimohan01@gmail.com

1. What is meaning of Android Word?

· Robot with a human appearance.

2. What is Android?

· Open-source operating system (Not a Programming Language).

· Platform Independent.

· Introduced by Google in 2007.

· Based on Linux kernel.

· Primarily used for touch screen inputs - smart phones and tablet computers.

· Also used in Android TVS, Cars, Wrist Watches, game consoles, digital cameras, regular pc’s, etc.

· Android has 65.58% MARKET SHARE where IOS (27.24 %) and Windows (3.26 %)

[As of June 2016]

https://www.netmarketshare.com/operating-system-market-share.aspx?qprid=8&qpcustomd=1

Extended Questions

View all answers of extended questions on this page –

http://techendu.blogspot.in/p/android-basics-ex.html?m=1

A1. What do you mean by Open-source?

A2. What do you mean by Platform Independent?

A3. What is difference between drivers and kernel?

A4. What is the Linux Kernel and What Does It Do?

A5. Why only Linux kernel is used for the integration between h/w and s/w in android and why no other kernel ?

A6. Why are there so many different Android Kernels?

A7. Can you compare between Android and Windows?

A8. Can you compare Android and IOS?

A9. Explain Android TV's

A10. Explain Android Auto

A11. Explain Android Wrist Watch

A12. What is portable wi-fi hotspot?

3. Advance Features of Android OS

· Google Now (voice assistant)

· NFC (Near Field Communication)

· Use your phone with joystick to enjoy gaming experience

· Connect your phone with LED TV via MHL or micro HDMI cable

· Multi-tasking future that is Task Switcher

· Data usages(check and also set limit for devices)

Extended Questions: http://techendu.blogspot.in/p/android-basics-ex.html?m=1

B1. Explain in Detail Google Now (voice assistant) -

B2. NFC (Near Field Communication)

4. Inventors of Android

· Andy Rubin

· Rich Miner

· Nick Sears

Must Read:

http://www.businessinsider.in/THE-STORY-OF-ANDROID-How-a-flailing-startup-became-the-worlds-biggest-computing-platform/articleshow/46717278.cms

5. What is the latest API level and version number of android as on March 2016?

Code name	Version number	Initial release date	API level
	1.0	September 23, 2008	1
	1.1	February 9, 2009	2
Cupcake	1.5	April 27, 2009	3
Donut	1.6	September 15, 2009	4
Eclair	2.0–2.1	October 26, 2009	5–7
Froyo	2.2–2.2.3	May 20, 2010	8
Gingerbread	2.3–2.3.7	December 6, 2010	9–10
Honeycomb^[a]	3.0–3.2.6	February 22, 2011	11–13
Ice Cream Sandwich	4.0–4.0.4	October 18, 2011	14–15
Jelly Bean	4.1–4.3.1	July 9, 2012	16–18
KitKat	4.4–4.4.4, 4.4W–4.4W.2	October 31, 2013	19–20
Lollipop	5.0–5.1.1	November 12, 2014	21–22
Marshmallow	6.0–6.0.1	October 5, 2015	23

6. Do all mobile phones support the latest Android operating system?

Some Android-powered phone allows you to upgrade to the higher Android operating system version. However, not all upgrades would allow you to get the latest version.

It depends largely on the capability and specs of the phone, whether it can support the newer features available under the latest Android version.

7. How do you give version numbers for application which is targeted for both mobiles and tablets? Will you give same version or different version?

Same because it is not based the version number that we differentiate between mobile version and tablet version, but it is by using fragments in the application

8. Tools required for Developing Android Apps

· JDK

· Eclipse + ADT Plug-in

· SDK Tools

· Android Studio by Google

Extended Questions:

What is JDK -- https://en.wikipedia.org/wiki/Java_Development_Kit

9. Different types of eclipse tools/flavors

Eclipse Versions:

Neon (4.6),

Mars (4.5),

Luna (4.4),

Kepler (4.3),

Juno (4.2, 3.8),

Previous to Juno (<=4.1),

Release	Main Release	Platform version

Oxygen	June 2017
Neon	22 June 2016	4.6
Mars	24 June 2015	4.5
Luna	25 June 2014	4.4
Kepler	26 June 2013	4.3
Juno	27 June 2012	4.2
Indigo	22 June 2011	3.7
Helios	23 June 2010	3.6
Galileo	24 June 2009	3.5
Ganymede	25 June 2008	3.4
Europa	29 June 2007	3.3
Callisto	30 June 2006	3.2
Eclipse 3.1	28 June 2005	3.1
Eclipse 3.0	28 June 2004	3.0

Platform Support: Windows, Mac, Linux/GTK

Organization Name: Google, Inc.

Sincere Thanks to Source:
http://stackoverflow.com/questions/4008976/difference-between-eclipse-europa-helios-galileo

10. Explain Tools in android?

The Android SDK and Virtual Device Manager:
It is used to create and manage Android Virtual Devices (AVD) and SDK packages. The AVD hosts an emulator running a particular build of Android, letting you specify the supported SDK version, screen resolution, amount of SD card storage available, and available hardware capabilities (such as touch screens and GPS).

The Android Emulator:
An implementation of the Android virtual machine designed to run within a virtual device on your development computer. Use the emulator to test and debug your Android applications.

Dalvik Debug Monitoring Service (DDMS):
Use the DDMS perspective to monitor and control the Dalvik virtual machines on which you're debugging your applications.

Android Asset Packaging Tool (AAPT):
Constructs the distributable Android package files (.apk).

AAPT allows you to view, create, and update Zip-compatible archives (zip, jar, apk). It can also compile resources into binary assets. It is the base builder for Android applications.

Android Debug Bridge (ADB):

Android Debug Bridge is a command-line debugging application shipped with the SDK. It provides tools to browse the device, copy tools on the device, and forward ports for debugging

Sincere Thanks to Source:

http://stackoverflow.com/questions/28234671/what-is-aaptandroid-asset-packaging-tool-how-it-works

11. What is AVD?

· Android Virtual Device(AVD) –EMULATOR

· Android SDK includes a mobile device emulator - a virtual mobile device that runs on your computer.

· Emulator allows the developers to work around an interface which acts as if it were an actual mobile device

· They can write, test and debug the code

· They are safe for testing the code

12. Explain ADT and SDK?

ADT stands for Android Developer Tools

·   Android Development Tools (ADT) is a plug-in for the Eclipse IDE that is designed to give you a powerful, integrated environment in which to build Android applications.

·   ADT extends the capabilities of Eclipse to let you quickly set up new Android projects, create an application UI, add packages based on the Android Framework API, debug your applications using the Android SDK tools, and even export signed (or unsigned) .apk files in order to distribute your application.

·   Developing in Eclipse with ADT is highly recommended and is the fastest way to get started. With the guided project setup it provides, as well as tools integration, custom XML editors, and debug output pane, ADT gives you an incredible boost in developing Android applications.

Sincere Thanks to Source:

https://marketplace.eclipse.org/content/android-development-tools-eclipse

SDK stands for Software Development Kit

A software developer's kit (SDK) is a set of programs used by a computer programmer to write application programs. Typically, an SDK includes a visual screen builder, an editor, a compiler, a linker, and sometimes other facilities. The term is used by Microsoft, Sun Microsystems, and a number of other companies.

In other words, it is a software development kit that enables developers to create applications for the Android platform. The Android SDK includes sample projects with source code, development tools, an emulator, and required libraries to build Android applications.

The Google Android SDK is a toolset that developers need in order to write apps on Android enabled devices. It contains a graphical interface that emulates an Android driven handheld environment, allowing them to test and debug their codes.

13. What is the Java SDK?

The JDK forms an extended subset of a software development kit (SDK). It includes "tools for developing, debugging, and monitoring Java applications". Oracle strongly suggests that they ^[who?] now use the term "JDK" to refer to the Java SE Development Kit.

14. Explain Android Architecture in detail

It contains:

Linux Kernel

Libraries

Android Framework

Android Applications

Android Framework

The Android Framework is an important aspect of the Android Architecture

Here you can find all the classes and methods that developers would need in order to write applications on the Android evs.

Android Applications - 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

Extended Question:

C1. Which phone do you use and what are its features?

C2. Sensors types

https://developer.android.com/guide/topics/sensors/sensors_overview.html

C3. What is difference between android and J2ME

http://kevinboone.net/android_j2me.html

15. Which Programming Language is used to develop an application in Android?

Java

XML

You can program android apps in C/C++ using NDK.

Extended Question:

D1. How you can develop android app in C/C++? What is NDK?

Find Answer here :
http://techendu.blogspot.in/p/android-basics-ex.html?m=1

16. Which is the most popular among all this languages

The main language supported is Java programming language.
Java is the most popular language for app development, which makes it ideal even for new Android developers to quickly learn to create and deploy applications in the Android environment.

17. Why cannot run standard Java byte code on android?

That's because Android uses Davik Virtual Machine and not traditional JVM.

The class file i.e the byte code for Android is first optimized even more to make it mobile friendly (Which usually has a custom format according to specifications of Dalvik VM), which differs from normal bytecode. Hence direct JAVA byte code won’t run.

18. Can you code in Java 8 for Android application? If no, why not?

Android does not currently support all Java 8 language features. However, the following features are now available when developing apps targeting the Android N Preview:

Default and static interface methods
Lambda expressions (also available on API level 23 and lower)
Repeatable annotations
Method References (also available on API level 23 and lower)
Type Annotations (also available on API level 23 and lower

Note: Type annotation information is only available at compile time, and not during runtime.

https://developer.android.com/preview/j8-jack.html

19. How Android app runs inside android mobile

Since Android code is written in Java, they are also compiled first and then executed but the JVM for which the byte codes are generated is different than standard JVM.
The Dalvik JVM is used to run Android app

20. What is Dalvik Virtual Machine(DVM) / Dalvik Executable File

· Just like Java application run on HotSpot,Android Application runs on the Dalvik Virtual Machine i.e; its Android's Virtual Machine

· It is an interpreter-only virtual machine which executes files in Dalvik Executable (.dex) format.

· Android uses DVM which requires a special byte code.

· We need to convert Java class files into Dalvik Executable files using an Android tool called "dx"

· In normal circumstances, developers will not be using this tool directly and build tools will care for the generation of DVM compatible files

· Dalvik Executable files have .dex extension and are zipped into a single .apk file on device

· .dex files can be created by automatically translating compiled applications written in the Java programming language

· Android programs are compiled into .dex (Dalvik Executable) files to execute with DVM

· .dex files are light weight when compared to .class files, and takes less memory and runs faster.

· DEX files are used to initialize and execute applications developed for the Android mobile OS

· DVM (Dalvik Virtual Machine) where an android application runs, can understand only .dex files.

· It can't understand .class files

· Dalvik serves as a virtual machine, and it is where every Android application runs.

· Through Dalvik, a device is able to execute multiple virtual machines efficiently through better memory management.

21. What is APK

APK - Android Package
The APK file is compressed AndroidManifest.XML file with extension .apk
It is having application code(.dex files),resource files and other files which are compressed into single .apk file

Sincere Thanks to Sources:

https://www.javacodegeeks.com/

http://career.guru99.com

http://stackoverflow.com

http://www.howtogeek.com

http://android.stackexchange.com

https://en.wikipedia.org

http://www.geekinterview.com

http://www.careerride.com

http://www.itechaleart.com

http://www.durgasoft.com

http://www.geeksforgeeks.org
https://en.wikipedia.org/