300+ Q&As - Ace your Android Developer Test, Interview

Explore how Android activities serve as entry points and UI, master the activity lifecycle, and learn launch modes—standard, single top, single task, and single instance—plus back stack basics.

Explore fragments as reusable UI components that create multi-pane layouts and adapt to configuration changes. Learn their lifecycles, activity communication, and common subclasses like list, dialog, and web view fragments.

Learn how Android services run long tasks in the background without a user interface, including foreground, background, bound, and started services with lifecycle callbacks like onCreate and onStartCommand.

Explore how content providers in Android act as data repositories, exposing access to applications via the provider client object and enabling query, insert, update, and delete through a cursor.

Learn how broadcasts and broadcast receivers work, including system broadcasts and app subscriptions. Register receivers in the manifest or in code, and manage ordered, unordered, and local broadcasts with permissions.

Explore how intents act as messaging objects to request actions from other app components, including implicit, explicit, and pending types, with extras and data.

Explore Android notifications, including heads up alerts, app icon badges, notification actions, and expandable and grouped notifications, with channels and importance levels guiding user interruption.

Explore the Android manifest file, a configuration describing project details to the system and Play Store, including package name, components (activities, services, receivers, providers), permissions, and uses-permission and uses-feature tags.

Understand Android app permissions, including normal versus dangerous rights, requests, when system grants automatically or prompts user, and how manifest flags and permission groups govern access to sensitive user information.

Explain push notifications as messages from a central server to a specific user's device and how apps register with backend services to send them via FCM.

Explore how deep links and App Links open specific app content via URLs and become default handlers, and how manifest filters, App Links verification, and digital asset links establish trust.

Explore Android build configurations with top level and module level build.gradle files, including application id, dependencies, API vs implementation, build variants, flavors, manifest merging, proguard, and multi dex.

Explore Android app data storage options, including internal and external file storage, shared preferences, and databases with Room, and learn how content providers and content resolvers enable data sharing.

Learn how Android uses processes and threads, including Linux process creation, async tasks on the UI thread, and the role of handlers and thread pool executors.

Discover Android wearables and how companion apps connect to phones to process UI on the wearable, highlighting reduced resources and limited interaction versus phones.

Explore Android layout fundamentals: view and view group structure, common layouts (linear, relative, constraint, frame, grid), adapters, responsive and adaptive UI, and creating custom layout components by extending View.

Learn how styles define a view's appearance, including font color, font size, and background. Explore themes across the app and version-specific styles using values folders, with default material design theme.

Learn about Android dialogues, small windows that prompt decisions or data entry, including alert, date picker, time picker, and progress dialogs, plus creating a custom dialog with a layout.

Explore Android resources, including layouts, strings, drawables, colors, and how density and api folders organize resources. Learn how the R class accesses resources and how config changes restart the activity.

Master animations and transitions to give views a polished look, animate between two activities with option bundles, and use path interpolate with an emotion curve to create movement.

Explore what app widgets are and how they appear on the home screen, providing at-a-glance information. Learn widget types—information, collection, and control—and basic provider concepts.

Explore constraint layout to build large, complex layouts with a flat view hierarchy, compare its flexibility to relative layout, and learn constraints, guidelines, barriers, and chains.

Explore how a recycler view recycles view objects to display datasets, boosting ui rendering speed, flexibility, and ease of implementation, and learn the roles of the view holder and adapter.

Explore the view pager, a layout manager that enables left-right page flipping, and understand the pager adapter that populates pages. Learn to animate transitions by implementing the page transformer interface.

Explore how toasts provide simple feedback in a small pop up with space, and how gravity offsets position them; learn snack bars at the bottom that support actions via setAction.

Explore options, context, and pop up menus in Android, how long clicks open a floating, anchored menu, and how to define items in a standard format in the res/menu folder.

Explore Android settings and how preferences control app functionality and background behavior, including data synchronization with the cloud and persisting data via key-value pairs in shared preferences.

Explore how to implement Android search within an app using a searchable configuration, a content provider, and a searchable activity for queries and intents.

Master Android performance by identifying bottlenecks, optimizing Android vitals, and applying a lazy first approach to reduce redundant operations, defer tasks, and coalesce batch work.

Identify how memory leaks occur when memory is allocated but not freed, blocking garbage collection. Learn common causes, detection tools, and strategies to avoid leaks using weak references and unregistration.

Understand Android's ANR dialog and how a stalled main thread triggers not responding errors. Use strict mode and trace view to diagnose deadlocks and lock contention.

Explore unit testing concepts and their role in preventing regressions and enabling continuous integration. Identify local vs instrumented tests and target 70–80 percent coverage using mosquito with Firebase Test Lab.

Master UI testing to verify functional requirements and quality, test many device screens quickly, reduce debugging time, and learn Espresso for writing UI tests, activity test rule, and intents validation.

Explore multi app testing, cross-app user flows, and AB testing using UI automata, the UI automated viewer, and the UI device to inspect layout and device state.

Explore design patterns in software engineering as general, repeatable solutions to common problems, covering four categories—creation, structural, behavioral, and concurrency—along with singleton, builder, abstract factory, adapter, iterator, and observer.

Examine Android design patterns like MVP, MVC, and MVVM, and learn how the view model wraps the model and provides observable data for the view.

Explore Firebase services like hosting, authentication, file storage, analytics, and cloud messaging, and learn to integrate crash reporting and AdMob with the latest library.

Explore git, an open source version control system, and GitHub, a web-based hosting service, and learn commits, branches, pull requests, and git flow.

Explore dagger 2, a dependency injection framework for Android, covering @Inject, constructor, field, and method injections, along with @Module, @Provides, and @Component annotations.

Explores RxJava, a reactive programming library for Java, exposing observable and observer concepts, onNext, onComplete, onError, operators, and the reactive manifesto guidelines.

Explore retrofit, a type-safe http client library for Android and Java, to retrieve and upload json data via rest-based web services, and learn get, post, rest architecture, and oauth.

Explore Glide, the image loading library for Android, with animated GIFs support, efficient loading and caching, and cropping and resizing transformations; compare it to Picasso and Fresco.

Explore butter knife, a view binding library using annotations to generate boilerplate code, binding views and events, and organizing multiple views with the bind view annotation.

Master agile methodologies and the Agile Manifesto values, and compare Scrum, Waterfall, extreme programming, test driven development, Caliban Campbell, and SOLID principles for modern software work.

Thank you for participating in the course and exploring Android questions and answers; feel free to reach out with questions or comments for future support.