Search test library by skills or roles
⌘ K

About the 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.

Covered skills:

  • Building Content with JSX
  • Class-Based Components
  • Communicating with Props
  • React State
See all covered skills

9 reasons why
9 reasons why

Adaface ReactJS Online Test is the most accurate way to shortlist ReactJS Developers



Reason #1

Tests for on-the-job skills

Ce test évalue les candidats sur les compétences suivantes:

  • React Fundamentals dans l'État, les accessoires et le cycle de vie des composants
  • Compréhension du DOM virtuel et comment React effectue la réconciliation
  • Tirer parti des méthodes de cycle de vie pour passer des appels AJAX
  • réagir la navigation et le transfert de données entre différents écrans
  • Gestion du code asynchrone en utilisant des rappels, des promesses, des générateurs et des fonctions asynchrones
  • Connexion des applications REACT avec les bibliothèques de gestion de l'État
  • Comprendre la nouvelle syntaxe de classe et créer des méthodes d'instance
  • Créer des crochets et des structures de contexte

En plus de React, le test évalue les candidats sur la capacité de codage JavaScript à l'aide de MCQ basés sur un scénario et de questions de codage.

Les informations générées à partir de cette évaluation de la réaction peuvent être utilisées par les recruteurs et les gestionnaires d'embauche pour identifier les meilleurs candidats pour les rôles de réaction.

Reason #2

No trick questions

Traditional assessment tools use trick questions and puzzles for the screening, which creates a lot of frustration among candidates about having to go through irrelevant screening assessments.

The main reason we started Adaface is that traditional pre-employment assessment platforms are not a fair way for companies to evaluate candidates. At Adaface, our mission is to help companies find great candidates by assessing on-the-job skills required for a role.

Why we started Adaface ->
Reason #3

Non-googleable questions

We have a very high focus on the quality of questions that test for on-the-job skills. Every question is non-googleable and we have a very high bar for the level of subject matter experts we onboard to create these questions. We have crawlers to check if any of the questions are leaked online. If/ when a question gets leaked, we get an alert. We change the question for you & let you know.

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

Medium

Context re-renders
Context
Solve
Review the following React code:
 image
Pick the correct statements:

A: The code renders 10 INDIAN RUPEE
B: The code renders 10 SINGAPORE DOLLAR
C: The code does not render anything and throws an error since JavaScript objects are not valid as React children
D: When the currency portion is clicked, the parent component is re-rendered
E: When the currency portion is clicked, parent component will skip the re-render because shouldComponentUpdate returns false
F: Parent component can be converted to a functional component with memoization (useMemo or memo) to avoid the re-render

Medium

Error Boundaries and Event handlers
Error Boundaries
Solve
Review the following React code:
 image
Notice that clicking on ‘Click Me’ will invoke handleClick which will throw an error. Also note that, ErrorBoundaryOne throws the error in getDerivedStateFromError. What will be rendered once ‘Click Me’ is clicked?
A: ErrorBoundaryOne will catch the error of MyComponent and <h1>C</h1> will be rendered
B: ErrorBoundaryOne will catch the error of MyComponent and its own error, <h1>C</h1> will be rendered
C: ErrorBoundaryTwo will catch the error of MyComponent and ErrorBoundaryOne, <h1>B</h1> will be rendered
D: ErrorBoundaryTwo will catch the error of MyComponent and ErrorBoundaryOne, <h1>B</h1><h1>C</h1> will be rendered
E: ErrorBoundaryTwo will catch the error of ErrorBoundaryOne. ErrorBoundaryOne will catch the error of MyComponent, <h1>B</h1> will be rendered
F: Error thrown in the click handler is not caught by any error boundary, ‘Click Me’ button will be rendered

Medium

Rhyme Reducer
Hooks
Solve
Which of the following React code snippets
- triggers the reducer ‘rhymeReducer’ to update the ‘song’ value to ‘Jack and Jill’
- renders the updated ‘song’ value
- does not produce any errors/warnings
 image
 image

Medium

Async Await Promises
Promises
Async-Await
Solve
What will the following code output?
 image
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

Easy

Bitcoin prices
Axios
Promises
Solve
Review the following JavaScript code and pick the correct options: 
 image
Assume that the API returns a successful 200 response code and a JSON object as the response body. What would the value of ‘a’ be after the code is executed?

Medium

My Module
Scope
Solve
What will the output of the following JavaScript code be?
 image
 image

Easy

Promise Resolve
Promises
Async-Await
Solve
What does the following code output? 
 image

Easy

Throw, Try, Async
Promises
Async-Await
Solve
What does the following JS code output?
 image

Easy

Registration Queue
Logic
Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount.
For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition.
⚠️⚠️⚠️ Note:
- The first line of the input is the length of the array. The second line contains all the elements of the array.
- The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function.
- You need to "print" the final result (not return it) to pass the test cases.

For the example discussed above, the input will be:
5
20 70 -40 30 -10

Your code needs to print the following to the standard output:
20 70 30 -40 -10

Medium

Longest Road
logic
hashmaps
Solve
A startup company E-Motors is building driverless automated cars. The car contains a sensor that checks the road quality for the next N meters to decide the optimal speed at which the cars should move. We are given recorded data by the sensor in the form of an array, where each element of the array is the rating given to 1 meter of the road in sequence. 

The rating given by the sensor is from 1 to 100, where 100 represents the road with the best condition, and any rating above 60 is optimal. Find the longest stretch of road in meters that is categorized as optimal by the sensor.

The input is an array of "strings" which needs to be converted from string to integer/number inside the function.

Medium

Visitors Count
Strings
Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. 
Example:

Input:
WWMMWWCCC

Expected Output: 
4W3C2M

Explanation: 
‘W’ has the highest count, then ‘C’, then ‘M’. 
⚠️⚠️⚠️ Note:
- The input is already parsed and passed to a function.
- You need to "print" the final result (not return it) to pass the test cases.
- If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’.
- If any of them have the same count, the output should follow this order - M, W, C.
🧐 Question🔧 Skill

Medium

Context re-renders
Context
3 mins
React
Solve

Medium

Error Boundaries and Event handlers
Error Boundaries
3 mins
React
Solve

Medium

Rhyme Reducer
Hooks
3 mins
React
Solve

Medium

Async Await Promises
Promises
Async-Await
2 mins
JavaScript
Solve

Easy

Bitcoin prices
Axios
Promises
2 mins
JavaScript
Solve

Medium

My Module
Scope
2 mins
JavaScript
Solve

Easy

Promise Resolve
Promises
Async-Await
2 mins
JavaScript
Solve

Easy

Throw, Try, Async
Promises
Async-Await
2 mins
JavaScript
Solve

Easy

Registration Queue
Logic
30 mins
Coding
Solve

Medium

Longest Road
logic
hashmaps
25 mins
Coding
Solve

Medium

Visitors Count
Strings
30 mins
Coding
Solve
🧐 Question🔧 Skill💪 Difficulty⌛ Time
Context re-renders
Context
React
Medium3 mins
Solve
Error Boundaries and Event handlers
Error Boundaries
React
Medium3 mins
Solve
Rhyme Reducer
Hooks
React
Medium3 mins
Solve
Async Await Promises
Promises
Async-Await
JavaScript
Medium2 mins
Solve
Bitcoin prices
Axios
Promises
JavaScript
Easy2 mins
Solve
My Module
Scope
JavaScript
Medium2 mins
Solve
Promise Resolve
Promises
Async-Await
JavaScript
Easy2 mins
Solve
Throw, Try, Async
Promises
Async-Await
JavaScript
Easy2 mins
Solve
Registration Queue
Logic
Coding
Easy30 minsSolve
Longest Road
logic
hashmaps
Coding
Medium25 minsSolve
Visitors Count
Strings
Coding
Medium30 minsSolve
Reason #4

1200+ customers in 75 countries

Brandon

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

Reason #5

Designed for elimination, not selection

The most important thing while implementing the pre-employment React.js Online Test in your hiring process is that it is an elimination tool, not a selection tool. In other words: you want to use the test to eliminate the candidates who do poorly on the test, not to select the candidates who come out at the top. While they are super valuable, pre-employment tests do not paint the entire picture of a candidate’s abilities, knowledge, and motivations. Multiple easy questions are more predictive of a candidate's ability than fewer hard questions. Harder questions are often "trick" based questions, which do not provide any meaningful signal about the candidate's skillset.

Reason #6

1 click candidate invites

Email invites: You can send candidates an email invite to the React.js Online Test from your dashboard by entering their email address.

Public link: You can create a public link for each test that you can share with candidates.

API or integrations: You can invite candidates directly from your ATS by using our pre-built integrations with popular ATS systems or building a custom integration with your in-house ATS.

Reason #7

Detailed scorecards & comparative results

Reason #8

High completion rate

Adaface tests are conversational, low-stress, and take just 25-40 mins to complete.

This is why Adaface has the highest test-completion rate (86%), which is more than 2x better than traditional assessments.

Reason #9

Advanced Proctoring


Comment personnalisez-vous le test pour les développeurs REACT seniors?

Les questions utilisées pour les tests de développeurs REACT senior sont basés sur des sujets de réaction avancés. Voici quelques sujets avancés que nous couvrons:

  • Utilisation de Babel et WebPack pour transpiler et regrouper le code
  • Comprendre comment JavaScript gère le code asynchrone à l'aide de la boucle d'événement avec la pile, le tas et la file d'attente
  • Utiliser des portails React pour rendre les enfants en dehors de la hiérarchie DOM
  • Nettoyage du code à l'aide des fonctions fléchées et de la liaison de méthode maître sans utiliser le mot clé Bind
  • Gestion de l'authentification avec React
  • Amélioration des performances des applications React (division du code, équilibrage de charge, mise en cache, optimisations de code)
  • Travailler avec des versions plus anciennes de React
  • Remplacer les bibliothèques de gestion des États comme Redux par le contexte
  • Implémentation d'animations dans la réaction

What roles can I use the React.js Online Test for?

  • 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

What topics are covered in the ReactJS Online Test?

Composants basés sur les classes
Composants fonctionnels
Accessoires
État
Événements
Listes
Crochets intégrés
Crochets personnalisés
Composants stylisés
Modules CSS
Fragments
Portails
Traitant des effets secondaires
États de transition
Formulaires et entrées
Gestion de l'État
Routage et navigation
Authentification
Animations
Webpack
Flexion
Le contexte
usestate
Utiliser EFFECT
usinducteur
usecontext
Réducteur
Authentification JWT
Singapore government logo

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.


85%
reduction in screening time

React.js Online Test FAQs

Puis-je évaluer React et TypeScript dans le même test?

Oui. Une fois que vous passez à un plan payant, vous pouvez demander une évaluation personnalisée. Nous personnalisons l'évaluation en fonction de votre description de poste et de votre soutien à l'évaluation de plusieurs compétences dans la même évaluation.

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.

Puis-je combiner plusieurs compétences en une seule évaluation personnalisée?

Oui absolument. Les évaluations personnalisées sont configurées en fonction de votre description de poste et comprendront des questions sur toutes les compétences indispensables que vous spécifiez.

Avez-vous en place des fonctionnalités anti-chétion ou de proctorisation?

Nous avons les fonctionnalités anti-modification suivantes en place:

  • Questions non googléables
  • IP Proctoring
  • Proctoring Web
  • Proctoring webcam
  • Détection du plagiat
  • navigateur sécurisé

En savoir plus sur les fonctionnalités de Proctoring.

Comment interpréter les résultats des tests?

La principale chose à garder à l'esprit est qu'une évaluation est un outil d'élimination, pas un outil de sélection. Une évaluation des compétences est optimisée pour vous aider à éliminer les candidats qui ne sont pas techniquement qualifiés pour le rôle, il n'est pas optimisé pour vous aider à trouver le meilleur candidat pour le rôle. Ainsi, la façon idéale d'utiliser une évaluation consiste à décider d'un score de seuil (généralement 55%, nous vous aidons à bencher) et à inviter tous les candidats qui marquent au-dessus du seuil pour les prochains cycles d'entrevue.

Pour quel niveau d'expérience puis-je utiliser ce test?

Chaque évaluation ADAFACE est personnalisée à votre description de poste / Persona de candidats idéaux (nos experts en la matière choisiront les bonnes questions pour votre évaluation de notre bibliothèque de 10000+ questions). Cette évaluation peut être personnalisée pour tout niveau d'expérience.

Chaque candidat reçoit-il les mêmes questions?

Oui, cela vous permet de comparer les candidats. Les options pour les questions du MCQ et l'ordre des questions sont randomisées. Nous avons Anti-Cheating / Proctoring en place. Dans notre plan d'entreprise, nous avons également la possibilité de créer plusieurs versions de la même évaluation avec des questions de niveaux de difficulté similaires.

Je suis candidat. Puis-je essayer un test de pratique?

Non. Malheureusement, nous ne soutenons pas les tests de pratique pour le moment. Cependant, vous pouvez utiliser nos exemples de questions pour la pratique.

Quel est le coût de l'utilisation de ce test?

Vous pouvez consulter nos plans de prix.

Puis-je obtenir un essai gratuit?

Oui, vous pouvez vous inscrire gratuitement et prévisualiser ce test.

Je viens de déménager dans un plan payant. Comment puis-je demander une évaluation personnalisée?

Voici un guide rapide sur Comment demander une évaluation personnalisée sur Adaface.

Join 1200+ companies in 75+ countries.
Try the most candidate friendly skills assessment tool today.
Ready to use the Adaface React.js Online Test?
Ready to use the Adaface React.js Online Test?
Chat with us
40 min tests.
No trick questions.
Accurate shortlisting.
Terms Privacy Trust Guide

🌎 Pick your language

English Norsk Dansk Deutsche Nederlands Svenska Français Español Chinese (简体中文) Italiano Japanese (日本語) Polskie Português Russian (русский)
Ada
Ada
● Online
Previous
Score: NA
Next
✖️