Practice
Resources
Contests
Online IDE
New
Free Mock
Scaler
Practice
Improve your coding skills with our resources
Contests
Compete in popular contests with top coders
Scaler
Explore Offerings by SCALER

Welcome to Interviewbit, help us create the best experience for you!

Currently, You are a:

Few details about your education

College/University *
Enter the name of your college
Branch *
Year of completion *

Few details about your education

College/University *
Enter the name of your college
Branch *
Year of completion *

Few details about your career...

Current Company *
Enter company name *
Experience *

You're all set!

Begin your success journey!

Sign Up using
Full name *
Email *
Password *

By creating an account, I acknowledge that I have read and agree to InterviewBit’s Terms and Privacy Policy .

Welcome back!

Log In using
Email *
Password *

React MCQ

  • ReactJS is a JavaScript library originally developed by Facebook.
  • it helps in building highly engaging single-page web apps.
  • react JS helps in breaking down the complex into simpler components.
  • NPX: It is an npm package that is expected to be done only once in a project.
  • Folder structure:
    • Readme.md:  it is used to generate an HTML summary.
    • .gitignore:  files that you do not want to push in GitHub.
    • public/index.html: HTML file of our react app. This is the page that will be loaded on starting the application.
    • src/index.js: JS File corresponding to index.html file.
    • src/app.js: The main component of any react app.  it acts as a container for all other components.
    • src/ app.css :  Hills in injection styling in react app
  • JSX:  it allows to write HTML in JavaScript and place them in DOM  without any child() or createElement() method.
  • Components in react:
    • they are nothing but reusable JavaScript function
    • even if the component does not depend on each other,  they merge inside a parent component to produce the final UI.
  • Benefits:
    • allows reusability of code
    • makes it easier to find a tailor
       

React MCQs

1. 

Which of the following is used in React.js to increase performance?

2. 

What is ReactJS?

3. 

Identify the one which is used to pass data to components from outside

4. 

Who created React.js?

5. 

In which language is React.js written?

6. 

What is Babel?

7. 

Identify the command used to create a react app.

8. 

Which of the following port is the default where webpack-dev-server runs?

9. 

How many elements can a valid react component return?

10. 

A state in React.js is also known as?

11. 

Which of the following method is used to access the state of a component from inside of a member function?

12. 

State whether true or false:  Props are methods into other components?

13. 

What are arbitrary inputs of components in react also known as?

14. 

In MVC, what does React.js act as?

15. 

State whether true or false: React.js covers only the view layer of the app.

16. 

Among The following options, choose the one which helps react for keeping their data uni-directional?

17. 

Using which of the following command can prevent default behaviour at in react?

18. 

Identify the smallest building block of React.JS.

19. 

What is ReactJS mainly used for building?

20. 

Which of the following function is used to change the state of react component?

21. 

Among the following which acts as the input of class-based component?

22. 

Among the following which is used to create a class inheritance?

23. 

Choose the correct data flow sequence of flux concept.

24. 

Total ways of defining variables in ES6 is?

25. 

Which of the following are two ways to handle data in react?

26. 

Among the corner which is a must-have for every ReactJS component?

27. 

ES6 stands for _________

28. 

Choose the method with refers to the parent class in ReactJS?

29. 

JSX stands for __________

30. 

The function which is called to render HTML to a web page in react?

31. 

Choose the functionality of setState?

32. 

Choose the method which is not a part of ReactDOM?

33. 

Choose the correct statement in the context of uncontrolled components in ReactJS?

34. 

In which directory is react component saved?

35. 

What is the functionality of a “webpack” command?

36. 

State whether true or false: React merges the objects you provide into the current state using setState().

37. 

State whether true or false: React creates virtual DOM in memory.

38. 

In react, the key should be?

39. 

Which company developed ReactJS?

40. 

Choose the component which should be overridden to stop the component from updating?

41. 

Which of the following is used to access a function fetch()  from h1 element in JSX?

42. 

When setState()  is called inside render() method, which of the following events takes place?

43. 

What happens if you render an input element with disabled = {false}?

44. 

When is useReducer used over useState in React component?

45. 

React is a ___________

46. 

Choose the library which is most often associated with react?

47. 

What is used to handle code-splitting?

48. 

Why is useLayoutEffect used?

49. 

Which of the following terms commonly described react applications?

50. 

Why is ref used?

Get Placed at Top Product Companies with Scaler Know More 
Get Placed at Top Product Companies with Scaler Know More 
Get Placed at Top Product Companies with Scaler
Sat transparent 640a34d454880bf68e3bfdf33f2389f2214043f59ad18b4c7f7b114e834fb257.svg

Point markers b3add1cc88e4996b2df6e0aedb9f0d1b65fa73c51b7ada8fbee3895a2aa11802.svg Personalised feedback report with solutions
Point markers b3add1cc88e4996b2df6e0aedb9f0d1b65fa73c51b7ada8fbee3895a2aa11802.svg Real life Interview Questions
Point markers b3add1cc88e4996b2df6e0aedb9f0d1b65fa73c51b7ada8fbee3895a2aa11802.svg Identify exact topics to improve

Your feedback is important to help us improve.
Free Mock Assessment
Fill up the details for personalised experience.
All fields are mandatory
Current Employer *
Enter company name *
Graduation Year *
Select an option *
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
Phone Number *
OTP will be sent to this number for verification
+1 *
+1
Change Number
Phone Number *
OTP will be sent to this number for verification
+1 *
+1
Change Number
Graduation Year *
Graduation Year *
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
*Enter the expected year of graduation if you're student
Current Employer *
Company Name *
Please verify your phone number
Edit
Resend OTP
By clicking on Start Test, I agree to be contacted by Scaler in the future.
Already have an account? Log in
Free Mock Assessment
Instructions from Interviewbit
Start Test