React JS Online Test

Pre-employment skills assessment test powered by AI chatbot

Adaface React.js Test will be customized to accurately evaluate on-the-job skills required for your role. This assessment test is useful when you are hiring candidates for roles like - React.js Developer, JavaScript Developer – React.js, Front End Developer – React.js, React.js consultant, Web Developer and can test candidate skills on topics like Mounting Method, Render Function, Password Principles, Component Optimize, Default Values for Properties, Handling Events, React Facts, etc.

  • amazon
  • paypal
  • ef
  • lovebonito
  • singapore-government
  • niyo
  • optimum
1. Scorecards
Ada creates a detailed scorecard for every conversation with section wise breakdown and a pass/ fail recommendation.
Ada creates a detailed scorecard for every conversation with section wise breakdown and a pass/ fail recommendation.

Adaface is your new secret weapon

Custom assessments

We create custom assessments based on your ideal developer persona. Check out our library of 700+ skills.

Higher test taking rate

Average test taking rate of 86% as compared to an industry standard of 50%. Read more about candidate friendly features here.

Friendly talent brand

Our AI chatbot Ada leaves your candidate with a smile at the end of the chat. Check out our candidate wall of love here.

"Chatbot format of coding assessments is amazing!"

"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

"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."

- Human Resources Manager, Singapore Government

About This Test

React online test is designed and validated by industry experts to help tech recruiters and hiring managers assess React and JavaScript programming skills of candidates. Top tech companies use our React Online test to reduce candidate screening time by 85%.

The test is designed to filter out candidates for roles like:

  • React Developer
  • Junior React Developer
  • JavaScript Developer
  • UI/UX Developer
  • Frontend Developer
  • Senior Frontend Developer
  • Web Developer
  • Full stack Developer

The test identifies candidates who have the following skills:

  • Excellent knowledge of frontend programming languages and related frameworks
  • Thorough understanding of React.js and its core principles
  • Deep knowledge of server-side scripting knowledge and interfacing
  • Knowledge of advanced libraries such as ReactJs, KnockoutJs, AngularJs, VueJs, SvelteJs
  • Familiarity with core JS concepts such as asynchronous request handling, AJAX, DOM
  • Knowledge of data structure libraries
  • Familiarity with JS developer basics such as HTML 5, CSS 3, pre-processors
  • Experience with writing unit and functional tests
  • Experience designing cross-browser and cross-device compatible UI
  • Ability to write reusable code

Why You Should Use This Test

The React Online test helps recruiters and hiring managers to identify qualified candidates from a pool of resumes, and helps in taking objective hiring decisions. It reduces the administrative overhead of interviewing too many candidates and saves expensive engineering time by filtering out unqualified candidates.

The Adaface tests screen candidates for the typical skills recruiters look for in a React developer:

  • Comprehension of basic React assumptions
  • A solid knowledge of JavaScript
  • Understanding of Component lifecycle, Higher-order components, React state and setState, React context
  • Experience working with Redux

The insights generated from this assessment can be used by recruiters and hiring managers to identify the best candidates for the role. Anti-cheating features enable you to be comfortable with conducting assessments online. The React developer test is ideal for helping recruiters identify which candidates have the technical skills to do well on the job.

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(100% free to get started, no credit card required)

Questions/ Topics in this Test

The React Online test will consist of ~15 MCQs, 1 coding challenge and 1 debugging challenge crafted by experts in JavaScript and React and will cover a broad spectrum of topics within React.

The exact number of questions and the topics will be chosen based on your job description and developer persona. Here is a list of topics for reference:

ES5 ES6/ ES7 HTML/CSS Mounting Method
Render Function Password Principles Component Optimize Default Values for Properties
Handling Events React Facts Storage Router
Ref Events Function Rendering
State Component ReactJS Basics React Basics
LifeCycle React Installation Webpack/ Browserify React Events
Methods React DOM props in React JSX
Props Overview Props Validation Component API Component Life Cycle
Forms Events Keys Flux Concept
Using Flux Animations Ajax Redux
Web development Conditional Rendering VDOM Component Life Cycle
Data Binding State Hook Effect Hook Reducer Hook
Portals Managing State Content Manipulation Higher Order Components

Sample React Online Test Question

Consider two ways to render following todos list (you can assume id of every todo is unique). Which of the following options is correct?

A: React throws an error when index is used as key like in OPTION 1.
B: To avoid inconsistencies its suggested to use unique keys across the entire app
C: To avoid inconsistencies its suggested to use unique keys across siblings
D: If todos get modified, OPTION 1 can lead to inconsistent state whereas OPTION 2 will lead to stable state as long as id's are unique among todos.

Frontend Engineer tests

You can combine multiple skills relevant to your Job description into a single custom Adaface JavaScript test. Here are some popular combinations for frontend roles. 

React JS + Javascript + NodeJS React JS + Javascript
React JS + Javascript + NodeJS + HTML/CSS React JS + Redux + Javascript + NodeJS + HTML/CSS
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(100% free to get started, no credit card required)

Fullstack Engineer tests

You can combine multiple skills relevant to your Job description into a single custom Adaface JavaScript test. Here are some popular combinations for fullstack roles. Read more about how we design custom tests.

React + JavaScript + SQL React + JavaScript + MySQL React + JavaScript + PostgreSQL React + JavaScript + Java + + Spring React + JavaScript + Java + Spring + SQL
React + JavaScript + Java + SQL React + JavaScript + Java + MySQL React + JavaScript + Java React + JavaScript + Python + Django React + JavaScript + Python + Django + SQL
React + JavaScript + PHP React + JavaScript + PHP + Laravel React + JavaScript + PHP + SQL React + JavaScript + PHP + MySQL React + JavaScript + PHP + Laravel + SQL

Sample Online Git Test Question

We are using git versioning for a project and while under development, a developer added an unfinished file to git that they didn't want to commit (using 'git add' command). Which of the following would you suggest to revert the mistake?


A: git rm

B: git rebase

C: git reset

D: git remove

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(100% free to get started, no credit card required)

Score Distribution

You should 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- tandardized 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.


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 5000+ 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 what we do differently at Adaface here.

Do you have any anti-cheating features in place?

We have the following anti-cheating features in place:

  1. Web proctoring
  2. Webcam proctoring
  3. Plagairism detection
  4. Non-googleable questions
  5. Secure browser

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. As in an assessment is optimizing to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best developer for the role. So the ideal way to use an assessment is to decide a threshold score (typically 60%, 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 developer persona (our subject matter experts will pick the right questions for your assessment from our library of 5000+ questions). This assessment can be customized for Java developer roles for any experience level (unless the role is primarily a leadership/ non-programming role, we do not recommend you a use any automated assessments in that case).

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 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 an engineer. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment.

What is the cost for using the React.js Test?

Please get in touch, we'll create a custom plan for you based on the number of assessments you need.

Can I get a free trial?

You can sign up for free and check out the platform here. The dashboard has a sample assessment for you to review the quality of questions and check out the candidate experience of a chat based assessment. Since our questions are premium, we are unable to share sample questions for a particular skill/ technology.

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

Check out our quick guide on requesting a custom assessment here.

How do I use this?

Step 1

You request a custom assessment via the dashboard.

Step 2

Our subject matter experts review your assessment request and select the right questions to evaluate candidates for that role from our library of 5000+ questions.

Step 3

You get an email when the assessment is ready for use (within a maximum 48 hours of creating the request).

Step 4

Voila! You can start inviting candidates. You can read more about custom assessments here.

Get started for free

(100% free to get started, no credit card required)

About The Role

React is a declarative, efficient, and flexible JavaScript library for building user interfaces. React combines the speed of JavaScript and uses a new way of rendering webpages, making them highly dynamic and responsive to user input. 

The team behind React managed to increase the speed of updates by using virtual DOM. Unlike other frameworks that work with the Real DOM, ReactJS uses its abstract copy – the Virtual DOM. Another advantage that Facebook introduced with React is the ability to reuse code components of a different level anytime, another meaningful time-saving effect.

Typical responsibilities of a React Developer include:

  • Developing new user-facing features using React.js
  • Developing new client-side ReactJS components for modern web and mobile applications
  • Building reusable components and front-end libraries for future use
  • Translating designs and wireframes into high quality code
  • Optimizing components for maximum performance across a vast array of web-capable devices and browsers
  • Improving product quality through code reviews, write effective unit tests and collaborate with Q&A to implement automation testing

Interview Questions

Candidates who pass Adaface React Online test can be taken for second round interviews. Here are top React interview questions for your reference.

Shortlist the best talent today

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(100% free to get started, no credit card required)


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Innov8 Coworking, 20th Main Rd, 7th Block, Koramangala, Bangalore, Karnataka, India 560095
© 2020 Adaface Pte. Ltd.

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