10+ Deltaclass Technology Solutions Interview Questions and Answers

Design patterns are reusable solutions to common software problems.

• Creational patterns: Singleton, Factory, Abstract Factory, Builder

• Structural patterns: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy

• Behavioral patterns: Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor

• We use design patterns to improve code readability, maintainability, and scalability.

• They provide a common language...read more

Currying is a technique in functional programming where a function with multiple arguments is transformed into a sequence of nested functions, each taking a single argument.

• Currying helps in creating reusable functions and partial application.

• In JavaScript, currying can be achieved using closures and nested functions.

• Example: const add = (a) => (b) => a + b; const add5 = add(5); console.log(add5(3)); // Output: 8

Promises in JS are objects representing the eventual completion or failure of an asynchronous operation. Async/await is a syntactic sugar for working with promises.

• Promises are used to handle asynchronous operations in JavaScript.

• They can be in one of three states: pending, fulfilled, or rejected.

• Async/await is a modern way to work with asynchronous code in JavaScript, making it easier to read and write.

• Async functions return a promise, allowing you to use the await keyword t...read more

Currying is a technique in functional programming where a function with multiple arguments is transformed into a sequence of nested functions, each taking a single argument.

• Currying helps in creating reusable functions and partial application.

• In JavaScript, currying can be achieved using closures and nested functions.

• Example: const add = (a) => (b) => a + b; const add5 = add(5); console.log(add5(3)); // Output: 8

Vite is a build tool that focuses on fast development, while Webpack is a more versatile and powerful build tool.

• Vite is designed for fast development with instant server start and hot module replacement.

• Webpack is a more versatile tool that can handle complex configurations and optimizations.

• Vite uses ES modules natively for faster bundling, while Webpack requires additional plugins for the same functionality.

• Vite is best suited for small to medium-sized projects, while Webp...read more

Webpack is a mature and feature-rich bundler, while Vite is a newer and faster build tool focused on development experience.

• Webpack is a mature and feature-rich bundler that is highly configurable and widely used in the industry.

• Vite is a newer build tool that focuses on providing a faster development experience by leveraging ES modules and server-side rendering.

• Webpack requires a configuration file (webpack.config.js) to set up the build process, while Vite has zero-config s...read more

Closure in JavaScript allows a function to access variables from its outer scope even after the outer function has finished executing.

• Closure is created when a function is defined within another function and the inner function references variables from the outer function.

• The inner function maintains a reference to the outer function's scope, allowing it to access those variables even after the outer function has returned.

• Closures are commonly used in event handlers, callbacks...read more

Explanation of CSS specificity hierarchy

• Inline styles have the highest specificity

• IDs have higher specificity than classes and elements

• Multiple selectors with the same specificity are resolved by the order in which they appear in the stylesheet

• The universal selector (*) has the lowest specificity

Clone a Todo Application UI using ReactJS, Sass

• Create a new ReactJS project using create-react-app

• Design the UI using Sass and implement it in ReactJS

• Use state and props to manage the todo list

• Add functionality to add, delete and mark tasks as complete

• Implement local storage to persist data

• Test the application thoroughly