Coding

In a distributed microservices architecture, what does the Circuit Breaker pattern achieve?

1 Mark(s)

Ensures real-time data synchronization.
Prevents cascading failures by stopping calls to a failing service
Balances load among different instances.
Handles API rate-limiting dynamically.

What does the React Context API use to avoid prop drilling

1 Mark(s)

Redux store
Higher-order components
The useReducer hook
The useContext hook

Where do you configure the minimum SDK version in Android Studio?

1 Mark(s)

build.gradle file
AndroidManifest.xml
proguard-rules.pro
app.properties

In Java, which is a drawback of using synchronized blocks for thread safety?

1 Mark(s)

Causes memory leaks.
Introduces unpredictable behavior in threads.
Prevents multiple threads from accessing variables.
Decreases CPU performance due to lock contention.

In Spring, what is the main difference between @Transactional and @Async?

1 Mark(s)

@Transactional manages transactions, and @Async runs methods asynchronously.
Both are used for managing transactions.
@Transactional is for database operations, while @Async is for network calls only.
Both annotations force parallel execution of tasks.

What is the purpose of the CompletableFuture.allOf() method in Java?

1 Mark(s)

Cancels multiple futures at once.
Converts a synchronous task into asynchronous.
Creates an exception-safe future.
Combines multiple futures into a single future.

In ReactJS (commonly used with Java backends), which hook is used to handle side effects?

1 Mark(s)

useState
useContext
useEffect
useReducer

In Kafka, what ensures high availability of messages when a broker fails?

1 Mark(s)

Consumer group balancing.
Topic compaction.
Compression algorithms.
Partition replication

Android applications are packaged in what file format?

1 Mark(s)

APK
EXE
ZIP
JAR

How does the @ComponentScan annotation work in Spring Boot?

1 Mark(s)

Automatically registers all Java classes in the project as beans.
Scans specified packages for annotated Spring components.
Configures the application context to include external dependencies.
Declares external APIs for runtime communication.

How do you create a new Android Virtual Device (AVD) in Android Studio?

1 Mark(s)

Tools > SDK Manager > New AVD
Tools > AVD Manager > Create Virtual Device
File > New > Android Virtual Device
Build > New Device

In computer, what is the smallest and basic unit of information storage?

1 Mark(s)

a) bit
b) byte
3) newton
d) mega byte

In Java, which is a drawback of using synchronized blocks for thread safety?

1 Mark(s)

Causes memory leaks.
Decreases CPU performance due to lock contention.
Prevents multiple threads from accessing variables.
Introduces unpredictable behavior in threads.

In Docker, how can you ensure your Java Spring Boot application container restarts on failure?

1 Mark(s)

Use the restart: always policy in docker-compose.yml.
Set HEALTHCHECK in the Dockerfile.
Use docker ps to monitor the container manually.
Limit memory usage in the Dockerfile.

A program that can copy itself and infect a computer without the permission or knowledge of the owner is called what?

1 Mark(s)

a) Floppy
B) Virus
C) Java
D) Monitor

Android Studio throws a 'Gradle sync failed' error. What is the most probable cause?

1 Mark(s)

Gradle is not installed
The project files are missing
The Gradle version is incompatible or network issues
The AndroidManifest is corrupted

What does the @RestController annotation in Spring Boot do?

1 Mark(s)

Converts an application into a database.
Ensures thread safety in controllers.
Combines @Controller and @ResponseBody.
Links a model to a view.

In React, what is the purpose of useDeferredValue?

1 Mark(s)

It defers rendering of non-urgent UI updates.
It defers state updates until the component unmounts
It memoizes functions to prevent re-creation.
It delays fetching data from APIs.

How does the volatile keyword in Java affect multi-threading?

1 Mark(s)

Guarantees visibility of changes to variables across threads
Makes a variable constant across the application.
Prevents thread interference by locking variables.
Prevents a variable from being garbage-collected.

What is the difference between useEffect and useLayoutEffect?

1 Mark(s)

useLayoutEffect runs after rendering, while useEffect runs before rendering.
useEffect runs asynchronously, while useLayoutEffect runs synchronously after DOM mutations.
Both hooks behave identically.
useLayoutEffect is only used for managing timers.

What does the @EmbeddedId annotation signify in JPA?

1 Mark(s)

A compound primary key mapped by multiple fields in a single class.
A primary key mapped to an external class.
A field used for relationships between entities.
A generated value for primary key fields.

In Spring Boot, what happens if two @Bean methods return the same type but have no explicit name?

1 Mark(s)

Both beans are created with autogenerated names.
A BeanCreationException is thrown.
Only the first method's bean is registered.
Both beans override each other.

In Hibernate, which fetch strategy retrieves related entities only when accessed for the first time?

1 Mark(s)

Eager Fetching
Batch Fetching
Subselect Fetching
Lazy Fetching

In Java, how can you achieve a thread-safe singleton implementation?

1 Mark(s)

Use a synchronized method for instance creation
Declare the class as final.
Use multiple constructors.
Make the instance variable public.

What is the role of the Dalvik Virtual Machine (DVM) in Android?

1 Mark(s)

To manage file storage
To manage application components
To interpret and run bytecode for Android applications
To provide a graphical user interface

Which of these is a correct format of IP address?

1 Mark(s)

A) 192, 168, 1, 1
B) 192, 168, 111, 1111
C) 192, 168, 900, 1
D) 192, 900, 168, 1

Which company acquried sun microsystems on January 27, 2010?

1 Mark(s)

a) Apple Inc
b) Microsoft
c) Oracle Corporation
d) IBM

Which hook is primarily used to implement server-side rendering (SSR) with React?

1 Mark(s)

useSSR
useStaticRendering
None; React SSR requires a library like Next.js or frameworks like Remix.
usePreload

Which JPA query strategy prevents the N+1 Select Problem in relational databases?

1 Mark(s)

Using lazy loading by default.
Using EntityGraph annotations.
Writing custom SQL queries for each use case.
Fetching data using JOIN FETCH.

What is the correct way to create an immutable class in Java?

1 Mark(s)

Use final keyword for the class and variables only.
Make the class abstract.
Declare the class final, use private final fields, and provide no setters.
Only use the synchronized keyword for methods.

In Android architecture, which layer directly interacts with hardware?

1 Mark(s)

A Application Layer
B Application Framework
C Libraries
D Linux Kernel

Which feature of Hibernate allows fetching only the required columns from the database?

1 Mark(s)

Criteria API
Named Queries
Projections
Entity Graphs

Which JavaScript function is used to parse JSON strings into objects?

1 Mark(s)

JSON.parse()
JSON.stringify()
toString()
decodeJSON()

What is the purpose of the Application Framework layer in Android architecture?

1 Mark(s)

To provide reusable components and services for developers
To manage the underlying Linux Kernel
To store app data
To handle network requests

Coding : Question 1 of 34