Psyliq Mysql Developer Interview Questions and Answers

There are multiple ways to share data between apps, including using intents, content providers, broadcast receivers, and shared preferences.

• Using Intents: Allows apps to send and receive data through an Intent object.

• Content Providers: Enable apps to share data with other apps by exposing a structured set of data through a URI.

• Broadcast Receivers: Apps can send broadcasts to other apps to share data or events.

• Shared Pr...read more

The app lifecycle includes states like running in the background, onStop, and onRestart.

• App running in the background: When the app is not visible but still running, it is in the background state.

• onStop state: Occurs when the activity is no longer visible to the user.

• onRestart state: Follows onStop and is called when the activity is being re-displayed to the user.

AIDL stands for Android Interface Definition Language, used for inter-process communication in Android development.

• AIDL is a tool used to define the programming interface that clients and servers use to communicate with each other in Android.

• It allows different Android components to communicate with each other across different processes.

• AIDL files define the methods that can be called remotely, along with the data type

JNI stands for Java Native Interface, used to integrate Java code with native code written in languages like C/C++.

• Experience in writing Java code that interacts with native code through JNI

• Understanding of how to create and use JNI libraries

• Knowledge of passing data between Java and native code using JNI functions

A service is a piece of code that performs specific tasks or functions to support the overall functionality of a software application.

• Services are often used for tasks such as data processing, communication with external systems, or background tasks.

• Examples of services include web services, REST APIs, and microservices.

• Services can run independently of the user interface and can be accessed by multiple components with

Threads are independent sequences of execution within a process, while coroutines are cooperative routines that can pause and resume.

• Threads are managed by the operating system, while coroutines are managed by the programmer.

• Threads run concurrently and can execute in parallel on multiple cores, while coroutines are typically single-threaded.

• Threads have their own stack and memory space, while coroutines share the same...read more

Background tasks in Android can be performed using services, AsyncTask, JobScheduler, or WorkManager.

• Use Services for long-running tasks in the background

• AsyncTask for short background tasks that need to interact with the UI

• JobScheduler for deferrable background tasks that require network connectivity

• WorkManager for tasks that need to run reliably across different Android versions

UNION combines the results of two or more SELECT statements, while UNION ALL includes duplicates.

• UNION removes duplicate rows, while UNION ALL retains all rows including duplicates

• UNION is slower than UNION ALL as it performs a distinct operation

• UNION requires the same number of columns in the SELECT statements, while UNION ALL does not have this restriction

Generic collections allow storing any type of data, while non-generic collections are type-specific.

• Generic collections can store any type of data, such as List or Dictionary.

• Non-generic collections are type-specific, like ArrayList or HashTable.

• Generic collections provide type safety and better performance compared to non-generic collections.