Tech Mahindra Senior Java Developer Interview Questions, Process, and Tips

Q1. What is final and finally
Ans. 
final is a keyword in Java used to declare constants, while finally is a block used in exception handling to ensure code is executed regardless of an exception.
• final keyword is used to declare constants in Java

• final variables cannot be reassigned once initialized

• finally block is used in exception handling to ensure code is executed regardless of an exception

• finally block is often used to release resources like closing
Answered by AI
Add your answer
Q2. Brief description about the last project
Ans. 
Developed a web application for a financial institution to manage customer accounts and transactions.
• Used Java Spring framework for backend development

• Implemented RESTful APIs for communication between frontend and backend

• Utilized Hibernate for database interaction

• Integrated third-party payment gateway for transactions
Answered by AI
Add your answer

Q1. What is flatMap in java 8?
Ans. 
flatMap in Java 8 is a method used to transform each element of a stream into another stream and then concatenate all the streams into a single stream.
• flatMap is used to flatten nested collections in streams.

• It is commonly used with streams of collections or arrays.

• Example: List> list = Arrays.asList(Arrays.asList(1, 2), Arrays.asList(3, 4)); list.stream().flatMap(Collection::stream).forEach(System.out::println);
Answered by AI
Add your answer

Medium level Strings and Array questions

Q1. Find LCA of a node in BST
Ans. 
LCA of a node in BST is the lowest common ancestor of two nodes in a binary search tree.
• Traverse the BST from the root node to find the LCA of the given nodes.

• Compare the values of the nodes with the current node to determine the LCA.

• If one node is on the left subtree and the other is on the right subtree, the current node is the LCA.
Answered by AI
Add your answer
Q2. Optimise the above solution
Ans. 
Optimize the solution by using efficient data structures and algorithms.
• Use HashMap instead of ArrayList for faster lookup

• Implement caching to store previously calculated results

• Consider using multithreading for parallel processing
Answered by AI
Add your answer

Q1. In java How hasmap works internally
Ans. 
HashMap is a data structure that stores key-value pairs and uses hashing to retrieve values.
• HashMap uses an array of buckets to store key-value pairs

• The hash code of the key is used to determine the index of the bucket

• If multiple keys have the same hash code, they are stored in a linked list within the bucket

• HashMap allows null keys and values

• HashMap is not thread-safe and requires synchronization for concurrent access
Answered by AI
Add your answer
Q2. Write program in java to print even no by one thread and odd no by another thread
Ans. 
Program to print even and odd numbers using two threads in Java
• Create two threads, one for even numbers and one for odd numbers

• Use a loop to generate numbers and check if they are even or odd

• Print the numbers using the respective threads

• Use synchronization to ensure alternate printing of even and odd numbers
Answered by AI
Add your answer