What are the 10 Common React Interview Questions to Build a Successful Coding Career?
React is one of the most popular JavaScript libraries among developers because of its ability to build complex software easily. Some of the popular companies that use React to create their products are Netflix, Facebook, Shopify, Airbnb, and Pinterest. These companies used it to build scalable web applications with high performance. Therefore, in order to build a successful career in coding, the writing on the wall is pretty clear—get familiar with the principles of React. This blog discusses some popular React interview questions for coders and how to answer them.
Top 10 React Interview Questions for Coders
Let’s see the 10 most popular manager interview questions or team leader interview questions related to React.
1. Where is React Used?
How to approach: Before going into detail about the use cases of React, give a brief explanation of what ReactJS is and then talk about its key features. Then, mention four to five significant use cases of React.
Answer: React.Js is a JavaScript library commonly used for developing web-user interfaces. React.Js is a popular library because of its component-based architecture, which helps create complex UIs. Its Virtual DOM facilitates faster and more efficient web development. Moreover, its vast community provides support to developers.
Some of the most popular use cases of React are:
- Developing rich user interfaces with less coding
- Create single-page applications or applications with complex user interface
- Build iOS or Android mobile apps and interactive web applications
- Create applications that require real-time updates, such as chatbots
2. How to Create Components in ReactJS?
How to approach: First, explain the meaning of components and their types quickly and then elaborate on the process of creating components in ReactJS.
Answer: Components in React are bits of code or UI building blocks that are independent and can be used. There are two types of components—class components and function components. We can create class components by extending React.component statements. The component’s name needs to start with an uppercase letter. Functional components use the return JSX.
The first step to creating components is creating a React project. Next, we create a simple, functional component and organize the project by creating a dedicated components folder in the director. In the folder, we create MyComponent.jsx and MyComponent.css files. Then we add the components to App.jsx.
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3. What are Forms in ReactJS?
How to approach: You can answer this Reach interview question for coders by defining forms and their role in web applications. Further explain how data form is managed.
Answer: Forms in ReactJS are similar to the forms in HTML. They handle user input and collect data, enabling users to interact with the webpage. Forms comprise text fields, buttons, or checkboxes and help authenticate users’ credentials, understand search input, or analyze selected data. React forms mainly use controlled components which help provide better control over form data.
4. What are Synthetic Events in React?
How to approach: This is one of the most popular React interview questions. For this question, you need to first explain what a cross-browser wrapper is and then describe synthetic events in detail.
Answer: To create cross-browser applications, React creates a wrapper that is similar to the native browser. Synthetic events in React are cross-browser wrappers for the browser’s native event system. They provide a familiar and consistent interface to handle events and ensure that the event properties across different browsers are standardized. Simply put, synthetic events in React are cross-border wrappers that combine the behavior of different events across different browsers into one Application Programming Interface (API).
5. How do Lists Work in React?
How to approach: Explain what are lists in React and their role in dynamic rendering. Here is how you can answer similar React interview questions:
Answer: Lists in React are mainly used to develop the UI of any website. They help create the menu, such as navigation bar menus on website pages. Hence, we need to render lists in React to ensure the smooth and efficient functioning of webpages. In React, we use the “map” function to first create a list of elements. All items have unique keys that help React identify altered items. Moreover, lists are rendered inside components using DOM.
6. How do You Write Comments in React?
How to approach: You can answer React interview questions related to comments by explaining the importance of comments in the code. Next, mention the syntax we need to use to add comments.
Answer: The main purpose of writing comments in React is to document our codes so that other developers can use them. We use JSX objects and JavaScript comments. Moreover, there are two approaches we can follow to write comments in React:
- Use /* */ JavaScript comments when we don’t use JSX code
- Try the JSX object with the JavaScript comments using curly brackets {/* */}
7. How is React Different From React Native?
How to approach: To answer React interview questions that involve differentiating React from another library, you should clearly define both libraries and explain their use cases. You can also mention practical use cases where React and the other library can be used. Here is an example:
Answer: React is a JavaScript library for developing user interfaces. On the other hand, React Native is a framework for building native mobile applications. The major difference between the two is that React is used for web development, whereas React Native is used for mobile development.
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8. How is React Different From Angular?
How to approach: Similar to the above question, this React interview question also requires defining React and Angular and explaining their use cases.
Answer: Both React and Angular are used for front-end development. However, React is a JavaScript library that creates the view layer of the Model View Controller (MVC), whereas Angular focuses on the complete MVC framework. React uses virtual DOM, whereas Angular uses a real DOM. We mostly use React for projects that require more flexibility and a component-based architecture. However, Angular is more suitable for projects with a structured framework.
9. What is a State in React and How Can You Implement it?
How to approach: For React interview questions on State, explain the meaning of State in React and why it is important.
Answer: In React, a State is an object used to determine how a component renders and behaves. It comprises data or information about the component. We manage the state within the component, which can change over time. To implement state-in-class components, we initialize the constructor and update it with the “this.setState” prompt.
10. How do You Create a React App?
How to approach: In React interview questions about creating a React app, first mention the prerequisites for creating a React app and then give a broad overview of the steps.
Answer: We can create a React app using the Create React App tool. It has a default configuration. The first step is to install Node.js. and npx. Next, we need to use the “npx create-react-app my-app” command followed by “cd my-app”, and “npm start” commands. These commands create a new React project. Then we can start building the application by editing the files.
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React is a popular library for web applications. Hence, if you are planning to build a career in web development, especially front-end development, you must learn the fundamentals of React. This will help if you are appearing for manager interview questions or team leader interview questions for coding or development roles. You can explore Emeritus’ online coding courses to learn various programming languages, their libraries, and coding skills and practices.
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