20+ Welspun Specialty Solutions Interview Questions and Answers

querySelector selects elements using CSS selectors, while getElementWithClass selects elements by class name.

• querySelector uses CSS selectors to select elements, while getElementWithClass selects elements by class name

• querySelector can select elements based on any CSS selector, while getElementWithClass is limited to selecting elements by class name

• querySelector returns the first matching element, while getElementWithClass returns a collection of elements with the specified c...read more

Object-oriented programming concepts include encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: bundling data and methods that operate on the data into a single unit (class). Example: class Car with properties like color and methods like start() and stop().

• Inheritance: allows a class to inherit properties and methods from another class. Example: class SUV inheriting from class Car.

• Polymorphism: ability of a method to do different things based on the obje...read more

Backend structure refers to the organization of server-side components that handle data processing and storage.

• Backend structure typically includes databases, servers, APIs, and application logic.

• Databases store and manage data, servers handle requests and responses, APIs facilitate communication between different components, and application logic processes data and implements business rules.

• For example, a backend structure for an e-commerce website may include a MySQL databa...read more

Finding the middle node of a linked list, explaining sorting algorithm used in Arrays.sort(), describing hashing, differentiating findElement and findElements, and writing xpath for dynamic elements.

• To find the middle node of a linked list, use the slow and fast pointer approach.

• Arrays.sort() method in Java uses a modified version of quicksort algorithm.

• Hashing is a technique used to map data to a fixed-size array, called a hash table, using a hash function.

• findElement is use...read more

let is block scoped while var is function scoped in JavaScript.

• let variables are limited to the block in which they are declared, while var variables are limited to the function in which they are declared.

• Using let can help prevent variable hoisting issues that may occur with var.

• let allows for better code readability and maintainability compared to var.

Closures in JavaScript allow functions to access variables from their outer scope even after the outer function has finished executing.

• Closures are created whenever a function is defined within another function.

• Inner functions have access to the outer function's variables even after the outer function has returned.

• Closures can be used to create private variables and functions in JavaScript.

Error codes in REST API

• 400 Bad Request - The request was invalid or cannot be served

• 401 Unauthorized - Authentication failed or user does not have permissions for the requested operation

• 403 Forbidden - The authenticated user does not have access to the requested resource

• 404 Not Found - The requested resource could not be found

• 500 Internal Server Error - An error occurred on the server side

• 503 Service Unavailable - The server is currently unavailable

React is a JavaScript library for building user interfaces.

• React is used for creating interactive UI components.

• It allows for efficient updating of the UI by only re-rendering the components that have changed.

• React uses a virtual DOM to improve performance.

• Components in React can be reusable and composed together.

• React can be used with other libraries like Redux for state management.

Client server architecture is a model where client devices request services from a central server.

• Client devices initiate requests to a central server

• Server processes the request and sends back the response

• Examples include web applications, email clients, and online gaming

• Allows for centralized management and control of resources

Sort a stack without using any other data structure.

• Pop the top element and store it in a variable

• Compare the variable with the top element of the stack

• If the variable is smaller, push the top element back to the stack and repeat the process

• If the variable is larger, push it back to the stack and repeat the process

• Repeat until the stack is sorted in ascending order

Web sockets are a communication protocol that allows for real-time, two-way communication between a client and a server over a single, long-lived connection.

• Web sockets enable real-time updates on a website without the need for constant polling.

• They are commonly used in chat applications, online gaming, and live streaming services.

• Web sockets use the ws:// or wss:// protocol in URLs to establish a connection.

Multithreading is the ability of a CPU to execute multiple threads concurrently, allowing for improved performance and responsiveness.

• Multithreading allows multiple threads to run concurrently within the same process.

• Each thread has its own stack and program counter, but shares the same memory space.

• Multithreading can improve performance by utilizing multiple CPU cores efficiently.

• Examples of multithreading include web servers handling multiple client requests simultaneously ...read more

Design a Restaurant Management System with features for reservations, orders, menu items, and billing.

• Implement a reservation system for customers to book tables in advance.

• Include a feature for placing and managing orders for both dine-in and takeout.

• Create a menu management system for adding, updating, and removing menu items.

• Incorporate a billing system that calculates total costs and generates receipts.

• Ensure scalability by designing the system to handle a large number of...read more

Data modeling with Star Schema involves organizing data into a central fact table surrounded by dimension tables.

• Central fact table contains numerical data that is being analyzed

• Dimension tables provide context to the data in the fact table

• Each dimension table is connected to the fact table through foreign keys

• Star Schema is commonly used in data warehousing for efficient querying

KMP algorithm is used for pattern matching in strings by avoiding unnecessary comparisons.

• KMP stands for Knuth-Morris-Pratt algorithm

• It uses a prefix function to avoid unnecessary comparisons

• It has a time complexity of O(n+m) where n is the length of the text and m is the length of the pattern

• Example: Searching for 'abc' in 'ababcabcab' using KMP algorithm

The task is to find the longest palindromic substring in a given string.

• Use dynamic programming to solve the problem efficiently.

• Iterate through the string and expand around the center to check for palindromes.

• Keep track of the longest palindromic substring found so far.

• Handle both odd and even length palindromes separately.

• Return the longest palindromic substring found.

APIs in backend are interfaces that allow different software applications to communicate with each other.

• APIs (Application Programming Interfaces) define the methods and data formats that applications can use to request and exchange information.

• They allow different software systems to communicate with each other, enabling seamless integration and interoperability.

• Examples of backend APIs include RESTful APIs, SOAP APIs, and GraphQL APIs.

• APIs in backend are commonly used for a...read more

Design a data structure for LRU cache with get and put operations, evicting least recently used item when capacity is reached.

• Implement a doubly linked list to keep track of the order of keys based on their usage

• Use a hashmap to store key-value pairs for quick access

• Update the order of keys in the linked list when get or put operations are performed

• Evict the least recently used item when the cache reaches its capacity

The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven layers.

• The OSI model stands for Open Systems Interconnection model.

• It divides network communication into seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• Each layer has specific functions and interacts with adjacent layers for data transmission.

• Example: The Physical layer deals with the physical connection b...read more

Designing a multistep form for user input

• Break down the form into multiple steps for better user experience

• Use progress indicators to show users their current step

• Allow users to navigate back and forth between steps

• Validate input at each step before proceeding to the next