Cognizant Reactjs Developer Interview Questions, Process, and Tips

Q1. React basic,event loop, Lazy Loading, Suspense, Javascript basics
Add your answer
Q2. Create counter application
Ans. 
Counter application using Reactjs
• Create a React component for the counter

• Use state to keep track of the count

• Implement functions to increment and decrement the count

• Display the count on the screen
Answered by AI
Add your answer

Q1. Splice & slice difference
Ans. 
Splice is used to add/remove elements from an array, while slice is used to extract a portion of an array without modifying the original array.
• Splice modifies the original array, while slice does not.

• Splice can add elements, remove elements, or replace elements in an array.

• Slice returns a new array with the selected elements from the original array.

• Example: const arr = [1, 2, 3, 4, 5]; arr.splice(2, 1); // removes elem...read more
Answered by AI
Add your answer
Q2. Coding question | How to reverse string
Ans. 
To reverse a string, iterate through the characters and swap them from start to end.
• Create an empty string to store the reversed result.

• Iterate through the characters of the input string from end to start.

• Append each character to the empty string to reverse the order.

• Return the reversed string.
Answered by AI
View 1 more answer

Q1. Basics of javascript and react concept.
Add your answer

Asked about vanilla.js in react interview.

Q1. Explain about the redux workflow
Ans. 
Redux workflow involves actions, reducers, and store to manage application state.
• Actions are dispatched to describe what happened in the application

• Reducers specify how the application's state changes in response to actions

• Store holds the application state and allows access to it

• Components can subscribe to the store to receive updates when the state changes
Answered by AI
Add your answer
Q2. What is virtual DOM
Ans. 
Virtual DOM is a lightweight copy of the actual DOM that React uses to improve performance by minimizing actual DOM manipulations.
• Virtual DOM is a concept where a lightweight copy of the actual DOM is created and manipulated by React.

• React uses the virtual DOM to efficiently update the actual DOM by only making necessary changes.

• When state or props change in a React component, a new virtual DOM representation is create...read more
Answered by AI
Add your answer

Q1. Wat is the hooks
Ans. 
Hooks are a feature in React that allow you to use state and other React features in functional components.
• Hooks were introduced in React 16.8.

• They allow you to use state and other React features without writing a class component.

• Some commonly used hooks are useState, useEffect, useContext, and useRef.

• Hooks must be used at the top level of a functional component.

• Hooks can be custom created as well.
Answered by AI
Add your answer