Android Interview Question Series for Freshers Part 01

Q: 01 What is Android?

Ans:  Android is a mobile operating system based on the Linux kernel and designed primarily for touchscreen devices such as smartphones and tablets. It was developed by Google and is used by many manufacturers of mobile devices. Android provides users with access to many apps through the Google Play Store and supports various features including GPS, camera, and more.

Q: 02 What are the features of Android architecture?

Ans:  The Android architecture includes the following key components:

I. Linux kernel: provides the underlying system services such as memory management, process management, and network stack. 

II. Libraries: provide various services and capabilities such as media codecs, SQLite database, and web browsing. 

III. Android runtime: includes the Dalvik virtual machine, which executes the Android app code.

IV. Application framework: enables developers to create and reuse components, manage the app activity lifecycle, and handle user events.

V. Applications: built on top of the framework, these are the app components that provide user-facing functionality.

The Android architecture also supports a rich set of framework APIs, including those for user interface, data storage, and connectivity, among others. Additionally, the architecture is designed to be highly customizable, allowing manufacturers to add their own features and services to their devices.

Q: 03 List the languages used to build Android.

Ans:  Android can be developed using the following programming languages:

I. Java: the official language for Android development, used for building the majority of Android apps.

II. Kotlin: a modern, concise, and expressive programming language that is fully interoperable with Java and can be used to build Android apps.

III. C++: can be used to build performance-critical parts of an Android app or to reuse existing code written in C++.

In addition to these, there are also other programming languages like C#, Python, and Dart that can be used to build Android apps through cross-platform frameworks such as Xamarin, Kivy, and Flutter, respectively. However, Java and Kotlin are the most widely used languages for Android development.

Q:04 What is Google Android SDK? Which are the tools placed in Android SDK?

Ans: The Android Software Development Kit (SDK) is a collection of tools and libraries provided by Google to help developers build Android apps. It includes 

I. Android emulator: a virtual device that runs on your computer and allows you to test your app in a simulated Android environment. 

II. ADB (Android Debug Bridge): a command-line tool used for debugging, testing, and managing Android devices.

III. Android Studio: the official Integrated Development Environment (IDE) for Android development, which includes features like code editing, debugging, and performance analysis.

IV. Aapt (Android Asset Packaging Tool): a tool that processes the resources of an Android app, such as images and strings, and creates the compiled resource file. 

V. Dex (Dalvik Executable) Tool: a tool that converts an Android app's compiled Java code into a format optimized for the Android runtime.

VI. SDK Manager: a tool that helps you download the latest version of the Android SDK and its components, as well as any updates or upgrades.

VII. Gradle: a build system used to automate the building, testing, and deployment of Android apps. 

 These are some of the critical tools included in the Android SDK, which provide developers with the necessary tools and resources to build high-quality Android apps.

Q:05 What is AAPT?

Ans:  AAPT (Android Asset Packaging Tool) is a tool that is part of the Android SDK. It is used to process the resources of an Android app, such as images, strings, and layouts, and create the compiled resource file (resources.arsc).

 AAPT performs tasks such as compiling resources, crunching PNG files, and packaging the processed resources into the final APK (Android Package) file that can be installed on an Android device. 

It also generates the R.java file, which is used by the app to access the resources at runtime. AAPT is a crucial tool in the Android development process and is used by developers to build and package their apps for deployment on Android devices.