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ReactJS Online Test

The React test uses scenario-based MCQ questions to evaluate the understanding of React component lifecycle, the ability to work with JSX, user events, React State, functional components, and Hooks to create dynamic React applications. The test has JavaScript MCQs to assess ES6 fundamentals, DOM, Fetch, Promises and Async / Await. The test includes coding questions to evaluate hands-on JavaScript programming skills.

Customized Based On:

  • Experience/ difficulty level
  • Multiple skills in 1 assessment
  • Job description/ role requirements

Covered Topics:

Building Content with JSX
Communicating with Props
Class-Based Components
React State
Lifecycle Methods
Handling User Input with Forms and Events
Making API Requests with React
Building Lists of Records
Using Refs for DOM Access
Understanding Hooks in React
Component and Route Navigation
Deploying a React App
Integrating React with State management libraries
Handling Authentication with React
Using the Context System with React
See full list
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The hiring managers felt that through the technical questions that they asked during the panel interviews, they were able to tell which candidates had better scores, and differentiated with those who did not score as well. They are highly satisfied with the quality of candidates shortlisted with the Adaface screening.

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Singapore Government

reduction in screening time

Sample React.js Online Test Questions

These are just a small sample from our library of 10,000+ questions. The actual questions on this React.js Online Test will be non-googleable.

🧐 Question🔧 Skill💪 Difficulty⌛ Time
Async Await Promises
What will the following code output?
A: 24 after 5 seconds and after another 5 seconds, another 24
B: 24 followed by another 24 immediately
C: 24 immediately and another 24 after 5 seconds
D: After 5 seconds, 24 and 24
E: Undefined
F: NaN
G: None of these


  • A
  • B
  • C
  • D
  • E
  • F
  • G
Promises Async-Await
JavaScriptMedium2 min
Functional components
Consider the following React components: What are the benefits of this refactoring?
A: Since Square doesn't have state, functional components are clean to maintain than class components
B: Transpiled code length of refactored code (OPTION 2) is greater than older code (OPTION 1) but it runs faster
C: It is easy to test refactored code since its a plain javascript function
D: There is a significant performance boost with refactored code since React optimizes functional components


  • A B
  • A D
  • A C
  • B D
  • B C
  • C D
  • A B D
  • B C D
  • A B C D
ReactMedium2 min
Prototypes and Scope
What will the following code output?


  • b0e1 5e b0e1 undefined
  • undefined 5e kj18
  • b0e1 5e kj18
  • b0e1 5e b0e1
JavaScriptMedium2 min
Promise Resolve
What does the following code output?


  • A, B and A, B
  • B, A and B, A
  • A, B and B, A
  • B, A and A, B
Promises Async-Await
JavaScriptEasy2 min
Throw, Try, Async
What does the following JS code output?


  • Data
  • Error
  • Finale
  • Data Finale
  • Error Finale
Promises Async-Await
JavaScriptEasy2 min

How to use the Adaface React.js Online Test

Start screening candidates within minutes with the ready-to-go React.js Online Test

1. Choose the most appropriate test for your role

2. Start inviting candidates to complete the assessment

3. Receive real time notifications and shortlist the best candidates

OR Customize the Adaface React.js Online Test according to your job description

1. Get a custom assessment from our library of 500+ skills within 48 hours

2. Start inviting candidates to complete the assesment

3. Receive real time notifications and shortlist the best candidates

Adaface React.js Online Test is trusted by enterprises worldwide

Morgan Stanley
SG Government
Ernst and Young
Optimum Solutions
United Nations
Love Bonito

About the Adaface React.js Assessment Test

Evaluate ReactJS technical and coding skills with Adaface skills assessment platform powered by an intelligent chatbot


Class-based components
Functional components
Built-in Hooks
Custom Hooks
Styled Components
CSS Modules
Dealing with side effects
Transitional states
Forms and Inputs
State Management
Routing & Navigation
JWT Authentication

Recommended Roles:

ReactJS Developer
Software Developer (React)
Full Stack Web Developer
Front End Engineer (React)
Software Engineer (ReactJS)
Web Developer
Senior ReactJS Developer
JavaScript Engineer (React)
Senior Web Engineer

Why You Should Use This React Test

This test evaluates the candidates on the following skills:

  • React fundamentals around State, props and the component lifecycle
  • Understanding of Virtual DOM and how React performs reconciliation
  • Leveraging lifecycle methods to make AJAX calls
  • React Navigation and data transfer between different screens
  • Handling asynchronous code using callbacks, promises, generators and async functions
  • Connecting React applications with state management libraries
  • Understanding new class syntax and creating instance methods
  • Creating Hooks and Context structures

Along with React, the test evaluates candidates on JavaScript coding ability using scenario-based MCQs and coding questions.

The insights generated from this React assessment can be used by recruiters and hiring managers to identify the best candidates for React roles.

How do you customize the test for Senior React developers?

The questions used for Senior React developer tests are based on advanced React topics. Here are a few advanced topics we cover:

  • Using Babel and Webpack to transpile and bundle code
  • Understanding how JavaScript handles asynchronous code using the Event Loop with the Stack, Heap and Queue
  • Using React Portals to render Children Outside the DOM Hierarchy
  • Cleaning up code using arrow functions and master method binding without using the bind keyword
  • Handling Authentication with React
  • Improving the performance of React applications (Code Splitting, Load Balancing, Caching, Code Optimizations)
  • Working with Older Versions of React
  • Replacing State management libraries like Redux with Context
  • Implementing animations in React

Distribution Of Test Scores

The actual score distribution will vary based on your candidate pipeline quality, but you should typically expect ~20% of the candidates to do well on Adaface assessments.

The score distribution for our assessments follow the normal curve. This is a good sign- standardized tests like SAT and GRE follow the normal distribution (bell curve).

Status quo assessments typically have the exact opposite of the bell curve (too many candidates getting close to 0, too many candidates getting close to 100 and too few candidates in the middle). This is typically because they focus on theoretical questions or trick questions, which are very binary in nature- either you know the trick/ theory or you don’t.

How Adaface Is Different

Adaface conversational assessments are reflective of on-the-job skills and see an 86% completion rate as compared to ~50% for traditional assessment platforms.



Theoretical questions/ puzzles

Feels like a test

One-size-fits-all assessments




Questions for on-the-job skills




React.js Online Test FAQs

Can I evaluate React and TypeScript in the same test?

Yes. Once you move to a paid plan, you can request for a custom assessment. We customize the assessment according to your job description and support evaluating multiple skills in the same assessment.

Can I evaluate React, JavaScript and HTML/ CSS in the same test?

Yes. The test already comes with MCQs to evaluate JavaScript fundamentals and coding questions to evaluate hands-on JavaScript programming skills. We can customize the test to include MCQ questions to evaluate HTML/ CSS skills.

What is a custom assessment?

Every role is different and requires a custom assessment to identify top candidates efficiently. Adaface subject matter experts understand your job description/ role requirements and pick the most relevant questions from our library of 10000+ questions to create a technical assessment that helps you find the qualified candidates in your candidate pipeline quickly. All custom assessments are set up based on the job description, role requirements, must-have skills, experience level and salary range within a maximum of 48 hours and you will get an email notification once it goes live.

Check out a sample assessment here (no credit card required).

Can I combine multiple skills into one custom assessment?

Yes, absolutely. Custom assessments are set up based on your job description, and will include questions on all must-have skills you specify.

How is Adaface different from other assessment tools?

We believe that status quo tech assessment platforms are not a fair way for companies to evaluate engineers because they focus on trick questions/ puzzles/ niche algorithms. We started Adaface to help companies find great engineers by assessing on-the-job skills required for a role. Read more about why we started Adaface.

Here's what's different with Adaface:

  • High quality non-googleable questions that test for on-the-job skills as opposed to theoretical knowledge.
  • A friendly conversational assessment with a chatbot, instead of sending a "test" to a candidate. This translates to a higher completion rate. Adaface assessments (86% candidate completion rate), as opposed to traditional tests (40-50% candidate completion rate)
  • Customized assessments for 700+ skills at different experience levels.

Do you have any anti-cheating or proctoring features in place?

We have the following anti-cheating features in place:

  • Web proctoring
  • Webcam proctoring
  • Plagairism detection
  • Non-googleable questions
  • Secure browser

Read more about the proctoring features.

How do I interpret test scores?

The primary thing to keep in mind is that an assessment is an elimination tool, not a selection tool. A skills assessment is optimized to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best candidate for the role. So the ideal way to use an assessment is to decide a threshold score (typically 55%, we help you benchmark) and invite all candidates who score above the threshold for the next rounds of interview.

What experience level can I use this test for?

Each Adaface assessment is customized to your job description/ ideal candidate persona (our subject matter experts will pick the right questions for your assessment from our library of 10000+ questions). This assessment can be customized for any experience level.

Does every candidate get the same questions?

Yes, it makes it much easier for you to compare candidates. Options for MCQ questions and the order of questions are randomized. We have anti-cheating/ proctoring features in place. In our enterprise plan, we also have the option to create multiple versions of the same assessment with questions of similar difficulty levels.

I'm a candidate. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment. However, you can use our sample questions for practice.

What is the cost of using this test?

You can check out our pricing plans.

Can I get a free trial?

The platform is completely self-serve, so here's one way to proceed:

  • You can sign up for free to get a feel for how it works.
  • The free trial includes one sample assessment (Java/ JavaScript) that you will find in your dashboard when you sign up. You can use it to review the quality of questions, and the candidate experience of a conversational test on Adaface.
  • To review the quality of questions, you can also review our public questions for 50+ skills here.
  • Once you're convinced that you want to try it out with real assessments and candidates, you can pick a plan according to your requirements.

I just moved to a paid plan. How can I request a custom assessment?

Here is a quick guide on how to request a custom assessment on Adaface.

With Adaface, we were able to optimise our initial screening process by upwards of 75%, freeing up precious time for both hiring managers and our talent acquisition team alike!

Brandon Lee, Head of People, Love, Bonito

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