React JS interview question part 1

 

Question 1: What is React JS?

Answer: React JS is a JavaScript library for building user interfaces. It is declarative, efficient, and flexible. React JS uses a component-based approach, which makes it easy to create and maintain complex UIs.

Question 2: What is JSX?

Answer: JSX is a JavaScript extension that allows you to write HTML-like code within your JavaScript code. JSX makes it easier to write React components and makes them more readable and maintainable.

Question 3: What is the virtual DOM?

Answer: The virtual DOM is a lightweight representation of the real DOM. React JS uses the virtual DOM to efficiently update the real DOM when the state of a component changes.

Question 4: What are the advantages of using React JS?

Answer: React JS has a number of advantages, including:

• Declarative: React JS uses a declarative programming style, which makes it easier to write and maintain complex UIs. 
• Efficient: React JS uses the virtual DOM to efficiently update the real DOM, which results in fast performance. 
• Flexible: React JS is a very flexible library, and it can be used to build a variety of different types of UIs. 

Question 5: What are some of the best practices for writing React JS code?

Answer: Here are some of the best practices for writing React JS code:

• Use components: React JS is a component-based library, so it is important to use components to organize your code. 
• Use state management: React JS components can have state, but it is important to use state management tools to manage state in a scalable way. 
• Use JSX: JSX makes it easier to write React components and makes them more readable and maintainable. 
• Use the virtual DOM: The virtual DOM is one of the key features of React JS, so it is important to use it efficiently. 

Question 6: What is the difference between functional components and class components?

Answer: Functional components are simpler and easier to write than class components. Class components can be used to write more complex components with state and lifecycle methods.

Question 7: What are hooks?

Answer: Hooks are a new feature in React JS that allows you to use state and other React features in functional components. Hooks make functional components more powerful and flexible.

Question 8: What is React Router?

Answer: React Router is a library for routing in React JS applications. It allows you to define different routes in your application and navigate between them.

Question 9: What is Redux?

Answer: Redux is a state management library for JavaScript applications. It provides a way to manage state in a scalable and predictable way. Redux is often used with React JS applications.

Question 10: What are some of the common challenges of using React JS?

Answer: Some of the common challenges of using React JS include:

• Learning the different concepts and features of React JS. 
• Writing efficient and scalable React JS code. 
• Debugging React JS applications.