HCL Group Front end Developer Interview Questions and Answers

Q1. Mostly js questions, not so many of angular or react.
Add your answer
Q2. Like fizbuzz or things like that.
Add your answer

Q1. Introduction life cycle looks pipe @input @output
Add your answer

Q1. What is event bubbling
Add your answer
Q2. What is TDD and why TDD
Add your answer

Reactive form and crud operations pipes crud operations

Q1. Basic understanding of js and angular is must expeciallly how js works questions on arrays objects shallow deep copy
Add your answer

Q1. Let var const in JavaScript
Ans. 
var and const are used to declare variables in JavaScript, with var being mutable and const being immutable.
• var is used to declare variables that can be reassigned and updated

• const is used to declare variables that cannot be reassigned or updated

• let is another keyword used for declaring variables, similar to var but with block scope
Answered by AI
Add your answer
Q2. Error boundary and how to handle
Ans. 
Error boundary is a React component that catches JavaScript errors anywhere in a component tree and logs those errors.
• Error boundaries are React components that catch JavaScript errors in their child component tree.

• They are used to prevent the entire UI from crashing due to a single error.

• Error boundaries work like a JavaScript catch {} block, but for components.

• They are defined using componentDidCatch lifecycle method
Answered by AI
Add your answer
Q3. Event.bind and event.property
Add your answer
Q4. Use of never in typescript
Ans. 
The 'never' type in TypeScript represents a value that will never occur.
• Used to indicate that a function will not return a value

• Commonly used in union types to exclude certain values

• Helps catch potential errors at compile time
Answered by AI
Add your answer
Q5. What hooks you have used
Ans. 
I have used React hooks such as useState, useEffect, useContext, and useRef in my projects.
• useState

• useEffect

• useContext

• useRef
Answered by AI
Add your answer
Q6. What is difference between use reducer and use state
Ans. 
useReducer is preferred for managing complex state logic, while useState is simpler for basic state management.
• useReducer is more suitable for managing complex state logic and multiple state values

• useState is simpler and more straightforward for basic state management with a single value

• useReducer allows for more organized and centralized state updates through actions and reducers

• useState is commonly used for simple co
Answered by AI
Add your answer
Q7. Why we use state and props
Add your answer
Q8. How you will pass data from parent to child
Ans. 
Data can be passed from parent to child components in React using props.
• Pass data as props from parent component to child component

• Use state management libraries like Redux or Context API for complex data sharing

• Use callback functions to pass data from child to parent components
Answered by AI
Add your answer
Q9. Write your own custom hook
Ans. 
Custom hook to fetch data from an API
• Create a function that uses the useState and useEffect hooks

• Use the fetch API to make a request to the desired endpoint

• Return the fetched data and loading state in an array
Answered by AI
Add your answer
Q10. Explain map filter and reduce functions
Ans. 
Map, filter, and reduce are higher-order functions in JavaScript used to manipulate arrays.
• Map: Transforms each element in an array and returns a new array with the transformed elements.

• Example: [1, 2, 3].map(num => num * 2) returns [2, 4, 6].

• Filter: Returns a new array with elements that pass a certain condition.

• Example: [1, 2, 3].filter(num => num > 1) returns [2, 3].

• Reduce: Applies a function against an accumulator ...read more
Answered by AI
Add your answer
Q11. How you can clone an object
Ans. 
To clone an object in JavaScript, you can use the spread operator or Object.assign() method.
• Use the spread operator to create a shallow copy of an object: const clonedObj = { ...originalObj };

• Use Object.assign() method to create a shallow copy of an object: const clonedObj = Object.assign({}, originalObj);

• For deep cloning, you can use libraries like Lodash or write a custom function to recursively clone nested objects.
Answered by AI
Add your answer
Q12. What are the three stages of event propagation and how to handle it
Ans. 
Event propagation consists of three stages: capturing, target, and bubbling.
• Capturing phase: Events are captured from the outermost element to the target element.

• Target phase: Event reaches the target element where the event originated.

• Bubbling phase: Events bubble up from the target element to the outermost element.
Answered by AI
Add your answer
Q13. How to handle errors in your react application
Ans. 
Errors in a React application can be handled by using error boundaries, try-catch blocks, and displaying error messages to users.
• Use error boundaries to catch errors in components and display a fallback UI

• Wrap code that may throw errors in try-catch blocks to handle exceptions

• Use libraries like React Error Boundary to easily implement error handling

• Display error messages to users to inform them about the issue and poss
Answered by AI
Add your answer
Q14. Write code to call fake api and display the title where category is “some category “
Add your answer

Q1. It was a array question. I was told to return a object from a function which would contain getting all the array elements, adding a element, deleting a element. The test was on hacker rank.
Add your answer

Q1. This was basically a one on one round. I was asked basics of HTML, CSS and React. Questions like Hoisting, Prop Drilling, Context API. Not only do you need to know what the topics are. But I was asked to i...read more
Add your answer

Q1. Basic Company Details and Salary Negotiations
Add your answer

Q1. What is aptitude
Add your answer
Q2. Front end developer in how much are there
Ans. 
Front end developers are in high demand due to the increasing importance of user experience in web development.
• Front end developers work on the client side of web development, focusing on the user interface and user experience.

• They are responsible for implementing designs, optimizing performance, and ensuring cross-browser compatibility.

• Front end developers often use HTML, CSS, and JavaScript, as well as frameworks lik...read more
Answered by AI
Add your answer
Q3. 3 or 4 maximum that's it
Add your answer
Q4. What isreasoning
Ans. 
Reasoning is the mental process of thinking, understanding, and forming conclusions.
• Reasoning involves using logic and critical thinking to make sense of information.

• It helps in problem-solving and decision-making by analyzing and evaluating evidence.

• Types of reasoning include inductive reasoning, deductive reasoning, and abductive reasoning.
Answered by AI
Add your answer
Q5. How to get success interview
Add your answer

Q1. What is mean by dom
Ans. 
DOM stands for Document Object Model, which is a programming interface for web documents.
• DOM is a representation of the structure of a web page, allowing scripts to dynamically access and update the content, structure, and style of the page.

• It provides a way for scripts to interact with the elements on a web page, such as changing text, styles, and attributes.

• DOM is hierarchical, with elements nested inside other eleme...read more
Answered by AI
Add your answer
Q2. Explain promise in typescript
Ans. 
Promises in TypeScript are objects representing the eventual completion or failure of an asynchronous operation.
• Promises are used to handle asynchronous operations in a more readable and manageable way.

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

• Promises can be chained using .then() to handle success and .catch() to handle errors.

• Example: const myPromise = new Promise((resolve, reject) => { ...
Answered by AI
Add your answer
Q3. Explain hooks in javascript
Ans. 
Hooks in JavaScript are functions that let you use state and other React features without writing a class.
• Hooks were introduced in React 16.8 to allow functional components to have state and lifecycle methods.

• useState() is a hook that allows you to add state to functional components.

• useEffect() is a hook that allows you to perform side effects in functional components.

• Custom hooks are functions that allow you to reuse
Answered by AI
Add your answer
Q4. Write a program 1 to 100 prime numbers
Ans. 
Generate an array of prime numbers from 1 to 100.
• Iterate from 1 to 100 and check if each number is prime

• A prime number is only divisible by 1 and itself

• Start with a list of prime numbers and check divisibility
Answered by AI
Add your answer