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React.js Test
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React.js Test

The Reactjs online test helps tech recruiters and hiring managers to evaluate candidates’ skills. The React.js assessment helps hire for various job roles, including React.js Developer, JavaScript Developer, Front End Developer, React.js Consultant, and Fullstack Developer. Our tests help build winning teams by increasing the interview-to-selection ratio by up to 62% and reducing hiring time by up to 45%.

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React.js Online Test

Today, front-end frameworks and libraries have become essential to modern web development. React.js is an open-source JavaScript library that has gradually become the go-to framework for modern web development. With React.js, developers can create large web applications that use data and change over time without reloading the page. iMocha's React.js online test uses scenario-based MCQ and AI-LogicBox questions to evaluate the understanding of the React component lifecycle.

Two important use cases for Reactjs Online Test

#1 Identifying job-fit candidates based on job roles

You can create customized skill assessments for any given job role. Using this feature, you can choose questions from different skill types, including functional, technical, and soft skills. For example, with our customized Reactjs assessments, you can evaluate candidates’ knowledge of Mounting Method, React Facts, Password Principles, Handling Events, and Communication Skills and assess the best individuals for the job.

#2 Skill-gap analysis of your employees

iMocha allows you to measure employees' skill competency through Reactjs training assessments. It determines the existing skill level and identifies the areas for growth. It also measures the knowledge and impact of the training and traces individual employees’ progress. For example, you can use our Reactjs training assessments to identify a consultant’s knowledge about Handling Events, React Facts, and other skills and perform a skill gap analysis.

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How it works

Test Summary

React Developer test helps employers to hire job-fit candidates quickly, making unbiased employee performance appraisal decisions, reducing mass recruitment hassles, and more. Questions on mounting method, render function, password principles, and component optimization also helps you assess candidate's React JS skills. Our React JS coding test can be taken online by candidates from anywhere irrespective of timezone.

The Reactjs skills test helps you to screen candidates possessing the following skills:

  1. Thorough understanding of React.js and its core principles.
  2. Ability to develop user interface components and implementation using popular React.js workflows such as Flux or Redux.
  3. Excellent knowledge of core web fundamentals like HTML5, JavaScript (DOM manipulation and the JavaScript object model), and CSS3.
  4. Familiarity with server-side scripting knowledge and interfacing.
  5. Strong experience working with data structure libraries.
  6. Use our React.js assessment test or ask us to create a custom-made test including a skill set as per the job description.

Our different types of React.js online test will help you assess candidates' specific skills. These assessments are created by React.js specialists using their industry experience. Example: questions are on topics including Mounting Method, Render Function, Component Optimize, Handling Events, Default Values for Properties, etc.

You can pick the questions you like or request us to create more questions if required.

Useful for hiring
  • React.js Developer
  • JavaScript Developer – React.js
  • Front End Developer – React.js
  • React.js Consultant
  • Fullstack Developer – React.js
Test Duration
No. of Questions
Level of Expertise
Entry Level/Mid/Senior
Topics Covered

Mounting Method

Mounting method means putting elements into the DOM. React.js has four built-in methods that gets called, in this order, when mounting a component: constructor(), getDerivedStateFromProps(), render(), componentDidMount().

Render Function

The React function takes two arguments, HTML code and an HTML element. The purpose of this function is to display the specified HTML code inside the specified HTML element.

Password Principles

Here are some of the password principles you should follow to secure your React applications: Secure basic authentication of your React app, make sure that the HTML code is resilient, use allow list/blocklist and validation while URL parsing, and Implement a Web Application Firewall (WAF).

Component Optimize

In React, function components and PureComponent provide two different ways of optimizing React apps at the component level. Function components prevent constructing class instances while reducing the overall bundle size as it minifies better than classes.

Default Values for Properties

The defaultProps is a React component property that allows you to set default values for the props argument.

Handling Events

Just like HTML DOM events, react can perform actions based on user events. React has the same events as HTML: click, change, mouseover etc.
Sample Question
Choose from our 100,000+ questions library or add your own questions to make powerful custom tests.
Question type
Multiple Answer
Topics covered


Q 1. How do you create a component with multiple elements and no parent?
<Fruits />

const Fruits = props => [
<div key="apple">Apple</div>,
<div key="orange">Orange</div>

const Fruits = props => (
<div key="apple">Apple</div>
<div key="orange">Orange</div>
) ;
const Fruits = ['Apple', 'Orange'].map(fruit => <div key={fruit}>{fruit}</div>);

A helicopter view of the employee's progress
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You can customize this test by

Setting the difficulty level of the test

Choose easy, medium, or tricky questions from our skill libraries to assess candidates of different experience levels.

Combining multiple skills into one test

Add multiple skills in a single test to create an effective assessment and assess multiple skills together.

Adding your own
questions to the test

Add, edit, or bulk upload your coding, MCQ, and whiteboard questions.

Requesting a tailor-made test

Receive a tailored assessment created by our subject matter experts to ensure adequate screening.
How is Reactjs online test customized?
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We can customize this React.js online test to suit your needs. Our SMEs will refer to the job description and customize the assessments based on the required skills needed. Some include Mounting Method, Component Optimize, Handling Events, etc. Likewise, you can choose the difficulty level to assess candidates of different experience levels.

What are the certifications required for this role?
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There are multiple courses online that provide a React JS Certification course. These React JS Certifications will help you learn all the necessary concepts to be a React JS developer. Here are the top 5 courses that provide you a React JS Certification upon completion.

• Learn React – The complete React JS guide from Udemy

• React JS Certification – Full Stack Web Developer by Coursera

• Best React JS Course – Modern React with Redux from Udemy

• Learning React.js Training Couse – Lynda – LinkedIn Learning

• The Complete React Web Developer Course

For example, you can use our Reactjs training assessments to identify a consultant’s knowledge about Handling Events, React facts, and other skills and perform a skill gap analysis.

What are the most common interview questions for this role?
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Companies are looking to hire React developers because React is a popular and powerful tool for building user interfaces. As more and more companies move to the web and mobile platforms, they need skilled developers who can create fast, efficient, and scalable applications. React provides a great way to do this, and so there is high demand for developers who know how to use it.

Here's a list of all the common Reactjs interview questions that are frequently asked in interviews.

• What is JSX?

• What are the features of React?

• What is the virtual DOM?

• Why use React instead of other frameworks, like Angular?

• What is the difference between the ES6 and ES5 standards?

• What is an event in React?

Explore our carefully chosen Reactjs interview questions to evaluate candidates' technical skills and find the right fit for your team.

What are roles and responsibilities of React developer?
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An efficient ReactJS developer should perform specific defined tasks and follow responsibilities to get the best results. Here are the major ones that any ReactJS developer is supposed to follow:

· Leverage the inbuilt React toolkit for creating frontend features

· Constant interaction with other developer teams and design teams to discuss UI ideas

· Follow proper documentation for changes in application and further updates

· Create data visualization tools, libraries, and reusable code for prospects

· Integrate designs and wireframes within the application code

· Monitor interaction of users and convert them into insightful information

· Write application interface code with JavaScript

This blog post covers iMocha's Tech Recruitment Guide for Reactjs Developer Hiring.

What are the required skillsets of React developer?
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Some of the required skillsets are:

Technical Skills:

·     Strong proficiency in JavaScript, object model, DOM manipulation and event handlers, data structures, algorithms, JSX, and Babel.

·     Complete understanding of ReactJS fundamentals likeJSX, Virtual DOM, component lifecycle, etc.

·     Prior experience with ReactJS workflows like Flux, Redux,Create React App, and data structure libraries.

·     Understanding of RESTful APIs/GraphQL, HTML/CSS, ES6(variables and scoping, array methods), code versioning tools like GIT, SVN,etc., popular frontend development tools, CI/CD tools, DevOps, performancetesting frameworks like Mocha, Node + NPM.

·     Preferred degree in Computer Science, InformationTechnology, or similar.



·     Competence in translating business needs into technical requirements.

·     Open-minded team player, willing to accept feedback and offer suggestions.

·     Good time management, project management, communication, and interpersonal skills

·     Good problem-solving and troubleshooting skills.

What is the package of React developer?
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There are multiple factors based on which the salary structure of a ReactJS developer depends. The average ReactJS Developer's salary in US starts at $92,000.