10+ Baerlocher India Additives Interview Questions and Answers

To use a custom object as a key in HashMap, override hashCode() and equals() methods in the custom object class.

• Override hashCode() method to generate a unique hash code for the custom object.

• Override equals() method to compare two custom objects for equality.

• Ensure immutability of the custom object to prevent unexpected behavior.

Use synchronized blocks or locks to ensure threads print numbers in sequence.

• Use synchronized blocks or locks to ensure only one thread can access the shared resource (number to be printed) at a time.

• Use a shared variable to keep track of the current number to be printed and update it after each thread prints its number.

• Use a loop to iterate from 1 to 10 and have each thread check if it is its turn to print the number.

Query to retrieve all employees with a salary greater than $50,000

• Use SELECT statement to retrieve data

• Use WHERE clause to filter employees with salary greater than $50,000

A component to display a table in a software application

• Use HTML and CSS to create the structure and styling of the table

• Use JavaScript to populate the table with data dynamically

• Consider adding features like sorting, filtering, and pagination for better user experience

Method overloading is when multiple methods in a class have the same name but different parameters.

• Allows multiple methods with the same name but different parameters to be defined in a class

• Parameters can differ in number, type, or order

• Example: void print(int num) and void print(String text) are overloaded methods

Closures are functions that have access to variables from their containing scope even after the function has finished executing.

• Closures allow functions to maintain access to variables from their parent scope

• They are commonly used in event handlers and callbacks

• Closures can be used to create private variables in JavaScript

React Js offers fast rendering, reusable components, virtual DOM, and easy integration with other libraries.

• Fast rendering due to virtual DOM

• Reusable components for efficient development

• Easy integration with other libraries like Redux

• Support for server-side rendering for improved SEO

• One-way data binding for predictable data flow

Anagrams in a given word

• Create a function to find all possible anagrams of a given word

• Use a hash table to store the frequency of each character in the word

• Generate all possible permutations of the characters and check if they exist in the hash table

Component lifecycle in React refers to the series of methods that are invoked at different stages of a component's existence.

• Mounting phase: constructor, render, componentDidMount

• Updating phase: render, componentDidUpdate

• Unmounting phase: componentWillUnmount

A thread is a lightweight process that can run concurrently with other threads within the same process.

• Threads allow for parallel execution of tasks within a single process

• Threads share the same memory space and resources within a process

• Examples include a web server handling multiple client requests concurrently

React JS is a JavaScript library for building user interfaces.

• React JS is maintained by Facebook.

• It allows developers to create reusable UI components.

• React JS uses a virtual DOM for better performance.

• Current stable version is 17.0.2 (as of September 2021).