People Tech Group Android Developer Interview Questions and Answers

Q1. Explain MVVM architecture
Ans. 
MVVM is an architectural pattern that separates the UI, business logic, and data layers in an Android app.
• Model: Represents the data and business logic of the application.

• View: Represents the UI components of the application.

• ViewModel: Acts as a mediator between the Model and View, handling communication and logic.

• Data binding: MVVM uses data binding to synchronize the View and ViewModel.

• Example: In an Android app, the...read more
Answered by AI
Add your answer
Q2. Explain Java Basic concept
Ans. 
Java is a high-level programming language known for its simplicity and versatility.
• Java is an object-oriented language

• It is platform-independent due to its 'write once, run anywhere' principle

• Java uses a virtual machine (JVM) to execute code

• It supports multithreading for concurrent programming

• Java has automatic memory management through garbage collection
Answered by AI
Add your answer
Q3. Explain Kotlin modifiers
Ans. 
Kotlin modifiers are keywords used to modify classes, properties, functions, and other elements in Kotlin programming language.
• Kotlin modifiers include 'public', 'private', 'protected', 'internal', 'open', 'final', 'abstract', 'override', 'lateinit', 'const', 'companion', 'inline', 'data', 'sealed', 'inner', etc.

• Modifiers like 'public', 'private', 'protected', and 'internal' control the visibility of classes, functions...read more
Answered by AI
Add your answer
Q4. Explain RXJava networking library
Ans. 
RXJava is a popular Java library for composing asynchronous and event-based programs using observable sequences.
• RXJava provides a powerful way to handle asynchronous operations by using observables and subscribers.

• It simplifies complex asynchronous code by allowing developers to chain operations and handle errors more easily.

• RXJava is commonly used in Android development for handling network requests and background tas...read more
Answered by AI
Add your answer
Q5. Explain Git commit , merge and rebase command
Ans. 
Git commit records changes to the repository, merge combines changes from different branches, and rebase moves changes to a new base commit.
• Git commit saves changes to the local repository with a message describing the changes made.

• Git merge combines changes from different branches into the current branch.

• Git rebase moves changes from one branch to another by applying each commit from the source branch to the target br
Answered by AI
Add your answer

Q1. Explain hooks in react
Ans. 
Hooks are a new addition in React 16.8 that allow you to use state and other React features without writing a class.
• Hooks are functions that let you use state and other React features in functional components.

• useState() is a hook that allows you to add state to functional components.

• useEffect() is a hook that allows you to perform side effects in functional components.

• Custom hooks are reusable functions that can contai...read more
Answered by AI
Add your answer

Create weather application in react native with unit test scripts

Q1. Structs vs Classes
Ans. 
Structs are value types and passed by value, while classes are reference types and passed by reference.
• Structs are used for small, simple data types like coordinates or colors.

• Classes are used for more complex data types that require inheritance or reference semantics.

• Structs are copied when passed around, while classes are passed by reference.

• Structs are stack allocated, while classes are heap allocated.
Answered by AI
Add your answer
Q2. Discussion about design patterns
Add your answer
Q3. OOPS discussion
Add your answer
Q4. Concurrency discussion
Add your answer

Q1. Oops based question
Add your answer
Q2. Solid principles and how to implement
Ans. 
Solid principles are a set of five design principles for writing maintainable and scalable code.
• Single Responsibility Principle: A class should have only one reason to change.

• Open/Closed Principle: Classes should be open for extension but closed for modification.

• Liskov Substitution Principle: Objects of a superclass should be replaceable with objects of its subclasses without affecting the program's correctness.

• Interfa...read more
Answered by AI
Add your answer

Tata using network layer

Q1. Self intro,swift basic to advance
Add your answer

Q1. Self intro , coding and technical question
Add your answer

Q1. Salary discussion from hr
Add your answer

Q1. Oops , programming, collection, java basic and Kotlin basic
Add your answer

Q1. What is static in Java?
Add your answer
Q2. What is singleton?
Add your answer
Q3. What is Coroutines?
Add your answer
Q4. What is dispatcher?
Add your answer
Q5. What is with context in Coroutines?
Add your answer
Q6. How to raise request parallel in Coroutines?
Add your answer
Q7. Scoped functions in Kotlin.
Add your answer
Q8. Background task in Android.
Add your answer
Q9. What is the difference between interface and abstract class in Java?
Add your answer
Q10. What is let function?
Add your answer

Q1. Types of job in kotlin coroutine
Ans. 
Types of jobs in Kotlin coroutine include launch, async, withContext, and runBlocking.
• launch: starts a new coroutine without blocking the current thread

• async: starts a new coroutine and returns a Deferred object with a result

• withContext: switches the coroutine context within a coroutine

• runBlocking: blocks the current thread until the coroutine inside it is completed
Answered by AI
Add your answer
Q2. What is Flow, Channel diffrent between StateFlow and SharedFlow
Ans. 
Flow is a cold asynchronous data stream, Channel is a hot asynchronous data stream. StateFlow is a hot asynchronous data stream with a state, SharedFlow is a hot asynchronous data stream without a state.
• Flow is a cold asynchronous data stream that emits values one by one.

• Channel is a hot asynchronous data stream that can have multiple subscribers.

• StateFlow is a hot asynchronous data stream that retains the most recent ...read more
Answered by AI
Add your answer
Q3. If Flow lifecycle aware
Ans. 
Flow lifecycle aware means using Kotlin Flow with lifecycle awareness in Android development.
• Flow lifecycle aware helps manage data streams in Android apps

• It ensures that data emissions are only observed when the lifecycle is in the appropriate state

• Example: Using Flow with LiveData to update UI components based on lifecycle events
Answered by AI
Add your answer
Q4. What is inline function and highorder function?
Ans. 
Inline functions are functions that are expanded in place at the call site, while high-order functions are functions that can take other functions as parameters or return them.
• Inline functions are expanded in place at the call site to improve performance.

• High-order functions can take other functions as parameters or return them.

• Example of high-order function: map() function in Kotlin.
Answered by AI
Add your answer