In this article, we present the top 100 Next.js interview questions and answers, designed to help you showcase your knowledge and ace your interview with confidence.
In today’s competitive tech landscape, mastering the right tools and frameworks is essential for any aspiring developer. Next.js, a powerful React framework for server-rendered applications, has become a popular choice for building modern web applications.
Whether you’re preparing for your next job interview or seeking to deepen your understanding of Next.js, having a solid grasp of common interview questions can make all the difference.
Q#1 What is NextJS?
Next.js is a React framework that provides infrastructure and simple development experience for server-rendered applications.
It extends the capabilities of React by providing features like static and server-side rendering, file-based routing, API routes, and more.
Key Differences:
API routes: Next.js allows creating backend API endpoints within the same application.
Server-side rendering (SSR): Next.js has built-in support for SSR, while React does not.Static site generation (SSG): Next.js can generate static HTML at build time.File-based routing: Next.js uses the file system to create routes automatically.
Q2: How does routing work in Next.js?
Next.js uses a file-based routing system. Each page in a Next.js app is a React component in the pages directory.
The file structure determines the routes of the application.
Q3: How can you fetch data in Next.js?
Next.js provides several methods for fetching data: getStaticProps, getServerSideProps, and getStaticPaths.
getStaticPaths: Used with getStaticProps for dynamic routing.
getStaticProps: Used for static site generation (SSG).
getServerSideProps: Used for server-side rendering (SSR).
4. What are dynamic routes in Next.js and how do you implement them?
- Dynamic routes allow you to create routes with dynamic parameters.
- You can implement dynamic routes by creating a file with square brackets in the pages directory.
5. How do you create API routes in Next.js?
- API routes provide a solution to build your API with Next.js. You can create an API endpoint by creating a file under the pages/api directory.
6. Explain the use of next/link and next/router.
next/link is used for client-side navigation between routes in Next.js. next/router provides methods to navigate programmatically and access the router object.
7. How do you use CSS in Next.js?
- Next.js supports various ways to style applications: CSS Modules, global CSS, and styled-components.
8. What is getInitialProps and how does it differ from getServerSideProps and getStaticProps?
getInitialProps is an older method to fetch initial data both on the server and client side, but it’s now generally recommended to use getServerSideProps or getStaticProps for SSR and SSG respectively.
Differences:
- getServerSideProps: Runs only on the server side and fetches data on each request.
- getStaticProps: Fetches data at build time and generates static pages.
9. How do you optimize images in Next.js?
- Next.js provides the next/image component for image optimization, which includes automatic resizing, optimization, and serving from a content delivery network (CDN).
10. Explain the use of middleware in Next.js.
- Middleware in Next.js allows you to run code before a request is completed. It can be used for tasks like authentication, logging, etc.
11. What is Incremental Static Regeneration (ISR) in Next.js?
Incremental Static Regeneration allows you to update static content after the initial build without rebuilding the entire site. You can specify a revalidation interval to update the content.
12. How does Next.js handle internationalization (i18n)?
- Next.js has built-in support for internationalized routing and locale detection. You can define the locales and default locale in the next.config.js.
13. How can you add custom headers in Next.js?
You can configure custom headers in the next.config.js file using the headers function.
14. What is the purpose of _app.js and _document.js in Next.js?
- _app.js: Customizes the default App component. It can be used to persist layouts, initialize state, or add global styles.
- _document.js: Customizes the HTML document structure. It can be used to modify the <html> and <body> tags and to add global meta tags or link tags
15. How do you handle environment variables in Next.js?
Next.js supports environment variables using .env files. You can define variables in .env.local, .env.development, or .env.production files.
16. How can you create a custom server with Next.js?
You can create a custom server with Next.js using Node.js or any other framework like Express. This allows more control over the server-side logic and middleware.
17. How do you use SWR for data fetching in Next.js?
- SWR is a React Hooks library for data fetching. It provides features like caching, revalidation, and error handling.
18. How can you handle redirects in Next.js?
You can handle redirects in Next.js using the redirects function in the next.config.js file.
19. How can you use TypeScript with Next.js?
- Next.js has built-in TypeScript support. You can start using TypeScript by creating a tsconfig.json file in the root directory and renaming your files from .js to .tsx.
20. What is the use of next/head?
- next/head is used to modify the <head> of your document. It allows you to add metadata, links, and scripts to the head of your pages.
Preparing for a Next.js interview can be a daunting task, but with the right resources and a solid understanding of the framework, you can approach it with confidence.
We hope these top 100 Next.js interview questions and answers have provided you with valuable insights and a clearer understanding of what to expect.
By studying these questions and practicing your responses, you’ll be well-equipped to demonstrate your expertise and secure that coveted position. Remember, preparation is key, and with diligent effort, you’re sure to succeed. Good luck!