Hoffensoft Android Developer Interview Questions and Answers

Intent is a messaging object used to request an action from another app component. There are two types of intents: explicit and implicit.

• Intent is used to start an activity, service, or broadcast receiver.

• Explicit intent specifies the component to be invoked by its name.

• Implicit intent specifies the action to be performed and optionally, the data to be used.

• Examples of implicit intents are opening a webpage or making a...read more

Activity and Fragment life cycles are a series of states that an Android component goes through during its lifetime.

• Activity life cycle includes onCreate(), onStart(), onResume(), onPause(), onStop(), and onDestroy() methods.

• Fragment life cycle includes onAttach(), onCreate(), onCreateView(), onActivityCreated(), onStart(), onResume(), onPause(), onStop(), onDestroyView(), and onDetach() methods.

• Both life cycles are im...read more

Activity is a single screen with a user interface, while fragments are a portion of the user interface in an activity.

• Activity is a standalone component that can be launched by an application.

• Fragments are reusable components that can be used in multiple activities.

• An activity can contain multiple fragments.

• Fragments have their own lifecycle and can be added or removed dynamically.

• Example: A music player app can have a...read more

ArrayList is a resizable array while HashMap is a key-value pair collection.

• ArrayList is ordered while HashMap is unordered

• ArrayList allows duplicate values while HashMap does not

• HashMap provides faster access to elements using keys

• Use ArrayList when you need to maintain the order of elements

• Use HashMap when you need to access elements using keys

Firebase Notification is a cloud messaging service provided by Google.

• Firebase Notification allows developers to send messages and notifications to their app users.

• It supports both Android and iOS platforms.

• It provides a console to send notifications to specific devices or topics.

• It also supports sending notifications based on user behavior and location.

• Firebase Notification can be integrated with other Firebase servic...read more

Java is a high-level, object-oriented programming language used for developing desktop, web, and mobile applications.

• Java is platform-independent and can run on any operating system.

• It is statically typed, meaning that variables must be declared before use.

• Java is used for developing Android applications, enterprise applications, and web applications.

• It is known for its security features, such as the Java Security Mana...read more

Oops concept in java

• Object-oriented programming paradigm

• Encapsulation, Inheritance, Polymorphism, Abstraction

• Classes and Objects

• Access Modifiers

• Interfaces and Abstract Classes

SDK stands for Software Development Kit. It is a set of tools and resources used for developing applications for a specific platform.

• SDK provides developers with APIs, libraries, and documentation to build applications for a specific platform.

• Android SDK includes tools like Android Studio, ADB, and Emulator.

• SDK helps developers to test, debug, and optimize their applications.

• SDK also provides sample code and templates ...read more

Retrofit and Volley are popular networking libraries for Android development.

• Retrofit is a type-safe HTTP client for Android and Java.

• Volley is a fast and efficient networking library for Android.

• Retrofit uses annotations to define API endpoints and request parameters.

• Volley provides easy-to-use APIs for making network requests and handling responses.

• Retrofit is best suited for RESTful APIs, while Volley is more versat...read more

Modules are independent units of code that can be used to build larger software systems.

• Modules can be reused in different projects

• They can be developed and tested independently

• Modules can be combined to form a larger system

• Examples include libraries, plugins, and frameworks

Signed APK is a single file that is signed and ready for distribution, while bundle is a publishing format that includes multiple APKs optimized for different device configurations.

• Signed APK is generated from a single APK file, while bundle generates multiple APKs.

• Signed APK is signed with a private key, while bundle is signed with an upload key.

• Bundle includes multiple APKs optimized for different device configuratio...read more