QBurst Technologies Interview Questions and Answers

Q1. Why stream api in Java?
Ans. 
Stream API in Java provides a functional approach to processing collections of objects.
• Allows for concise and readable code by using functional programming concepts like map, filter, and reduce.

• Enables parallel processing of data, improving performance for large datasets.

• Supports lazy evaluation, allowing for efficient use of resources.

• Example: List<String> names = Arrays.asList("Alice", "Bob", "Charlie"); names....read more
Answered by AI
Add your answer
Q2. Java code to filter even numbers from a list and store the square of those in another list
Ans. 
Java code to filter even numbers from a list and store the square of those in another list
• Create two ArrayLists to store the original list and the squared even numbers list

• Iterate through the original list and check if each number is even

• If the number is even, square it and add it to the squared even numbers list
Answered by AI
Add your answer
Q3. Java code to check two strings are anagram
Ans. 
Java code to check if two strings are anagrams
• Create a function that takes in two strings as parameters

• Convert both strings to char arrays and sort them

• Compare the sorted char arrays to check if they are equal
Answered by AI
Add your answer
Q4. Need of functional interfaces in java
Ans. 
Functional interfaces in Java are needed to enable the use of lambda expressions, which provide a concise way to implement single abstract method interfaces.
• Functional interfaces have exactly one abstract method and can have multiple default or static methods.

• They are used to enable the use of lambda expressions, which provide a concise way to implement the single abstract method.

• Examples of functional interfaces in Ja...read more
Answered by AI
Add your answer
Q5. How threads can be created in java
Ans. 
Threads in Java can be created by extending the Thread class or implementing the Runnable interface.
• Extend the Thread class and override the run() method

• Implement the Runnable interface and implement the run() method

• Use the Executor framework for managing threads
Answered by AI
Add your answer

Q1. Explain singleton design pattern.
Ans. 
The singleton design pattern ensures a class has only one instance and provides a global point of access to it.
• Restricts instantiation of a class to a single object.

• Provides a global access point to that instance.

• Commonly used for configuration settings, logging, and thread pools.

• Example in Java: Use a private constructor and a static method to get the instance.

• Thread-safe implementations can be achieved using synchron...read more
Answered by AI
Add your answer
Q2. Streaming query to get frequently occurring character.
Ans. 
Use Java Streams to count character occurrences in a string and find the most frequent one efficiently.
• Utilize Java Streams to process the string: `string.chars()` converts to an IntStream.

• Group characters using `Collectors.groupingBy()` to count occurrences.

• Sort the map by values to find the maximum occurrence: `map.entrySet().stream().max(Map.Entry.comparingByValue())`.

• Example: For input 'hello', the output should be...read more
Answered by AI
Add your answer
Q3. SQL query for outer join scenario
Ans. 
An outer join retrieves records from both tables, including unmatched rows from one or both sides.
• Outer joins can be LEFT, RIGHT, or FULL, depending on which table's unmatched rows you want to include.

• Example of LEFT JOIN: SELECT * FROM A LEFT JOIN B ON A.id = B.a_id; // Includes all from A and matched from B.

• Example of RIGHT JOIN: SELECT * FROM A RIGHT JOIN B ON A.id = B.a_id; // Includes all from B and matched from A...read more
Answered by AI
Add your answer

Q1. Questions related to Jwt token
Add your answer
Q2. Questions related to current project architecture
Add your answer

3 questions
1. Check the given string is reversed?
input: "worldhello" output: "true"
2. Check the given string is permutation of palindrome?
3. Sort a stack using an empty stack

Q1. Javascript basics
Add your answer
Q2. Nodejs basics questions
Add your answer

Q1. How do GO handle concurrency?
Ans. 
GO uses goroutines and channels to handle concurrency efficiently.
• GO uses goroutines to achieve concurrency. Goroutines are lightweight threads managed by the Go runtime.

• Channels are used to communicate between goroutines. They provide a safe way to pass data between concurrent processes.

• GO also has a built-in 'sync' package for synchronization primitives like mutexes and wait groups.

• GO's 'select' statement allows for ...read more
Answered by AI
Add your answer
Q2. What is defer in GO ? If there are multiple defers in a function, what will be order of execution of these?
Ans. 
defer in Go is used to delay the execution of a function until the surrounding function returns.
• Defer is used to ensure that a function call is performed at the end of the surrounding function, regardless of where the defer statement is located.

• If there are multiple defers in a function, they will be executed in Last In, First Out (LIFO) order.

• Example: func exampleFunc() { defer fmt.Println('First defer'); defer fmt.Pr...read more
Answered by AI
Add your answer