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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

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.

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

Options:

  • C
  • A D
  • A E
  • B D
  • B E
  • A D F
  • A E F
  • B D F
  • B E F

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 

C

will be rendered
B: ErrorBoundaryOne will catch the error of MyComponent and its own error,

C

will be rendered
C: ErrorBoundaryTwo will catch the error of MyComponent and ErrorBoundaryOne,

B

will be rendered
D: ErrorBoundaryTwo will catch the error of MyComponent and ErrorBoundaryOne,

B

C

will be rendered
E: ErrorBoundaryTwo will catch the error of ErrorBoundaryOne. ErrorBoundaryOne will catch the error of MyComponent,

B

will be rendered
F: Error thrown in the click handler is not caught by any error boundary, ‘Click Me’ button will be rendered

Options:

  • A
  • B
  • C
  • D
  • E
  • F

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

Options:

  • A B C D
  • B C D
  • B D
  • C D
  • B C
  • B
  • D

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

Options:

  • A
  • B
  • C
  • D
  • E
  • F
  • G

Easy

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

Options:

  • A, B and A, B
  • B, A and B, A
  • A, B and B, A
  • B, A and A, B

Easy

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

Options:

  • Data
  • Error
  • Finale
  • Data Finale
  • Error Finale

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.
    🧐 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

    Promise Resolve
    Promises
    Async-Await
    2 mins
    JavaScript
    Solve

    Easy

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

    Medium

    Longest Road
    logic
    hashmaps
    25 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
    Promise Resolve
    Promises
    Async-Await
    JavaScript
    Easy2 mins
    Solve
    Throw, Try, Async
    Promises
    Async-Await
    JavaScript
    Easy2 mins
    Solve
    Longest Road
    logic
    hashmaps
    Coding
    Medium25 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

    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 #6

    Detailed scorecards & comparative results

    Reason #7

    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 #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


    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

    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?

    Class-based components
    Functional components
    Props
    State
    Events
    Lists
    Built-in Hooks
    Custom Hooks
    Styled Components
    CSS Modules
    Fragments
    Portals
    Dealing with side effects
    Transitional states
    Forms and Inputs
    State Management
    Routing & Navigation
    Authentication
    Animations
    Webpack
    Flexbox
    Context
    useState
    useEffect
    useReducer
    useContext
    Reducer
    JWT Authentication
    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

    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.

    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.

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

    We have the following anti-cheating features in place:

    • Non-googleable questions
    • IP proctoring
    • Web proctoring
    • Webcam proctoring
    • Plagiarism detection
    • 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?

    Yes, you can sign up for free and preview this test.

    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.

    Join 1200+ companies in 75+ countries.
    Try the most candidate friendly skills assessment tool today.
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