Most Asked Next.js Interview Questions and Answers
Following is a list of most frequently asked Next.js interview questions and their answers.
1) What is Next.js?
Next.js is an open-source, lightweight React.js framework that facilitates developers to build static and server-side rendering web applications. It was created by Zeit. Next.js framework is based on React, Webpack, and Babel and allows us to write server-rendered React apps easily. It doesn't require any webpack configuration and only needs npm run dev start building your next feature-filled web application.
2) Why is Next.js used for? / Why do world's leading companies prefer Next.js?
If you want to build a complete web application with React from scratch, you have to fulfill the following points:
Next.js fulfills the above all requirements.
Reasons why the world's leading companies prefer Next.js:
Zero Setup: Next.js provides automatic code-splitting, filesystem-based routing, hot code reloading, and universal rendering; that's why the world's leading companies prefer it.
Fully Extensible: Next.js is fully extensible and has complete control over Babel and Webpack. It provides a customizable server, routing, and next plugins.
Ready for Production: Next.js is optimized for smaller build sizes, faster dev compilation, and many other improvements, making it a popular choice.
Next.js can Deploy Anywhere: Next.js is an open-source, lightweight React.js framework that facilitates developers to build static and server-side rendering web applications.
3) What is the process to install Next.js? / How to install Next.js?
Before installing Next.js, you must have installed Node.js on your system. Learn how to install Node.js on your system: https://www.javatpoint.com/install-nodejs
It requires NPM to start installing Next.js with all its dependencies.
Follow the steps given below to install Next.js:
4) What are the most prominent features of Next.js?
Following is a list of the most prominent features of Next.js that excite the developers most:
Besides this, Next.js also has some awesome features such as:
5) Which types of websites most popularly use Next.js?
Next.js is a popular framework of React.js that is most popularly used for building the following types of apps and websites:
6) Is it possible to use Next.js with Redux?
Yes. You can easily use Next.js with Redux.
7) What is the recommended method to fetch data in Next.js?
There are multiple ways to fetch data in Next.js, but Next.js itself recommends getInitialProps, an async function to retrieve data from anywhere. When we use getInitialProps to retrieve data, it receives a context object which has the following properties:
8) Give an example to demonstrate how do you set up CDN in Next.js?
To setup CDN in Next.js, the developers have to follow the steps given below:
To start, we have to first set up the "assetPrefix" setting and configure our CDN origin to support and resolve the domain that our Next.js is hosted on.
If the CDN is present on a separate domain, we have to set a configuration option as following:
9) Are Create-React-App and Next.js used for the same thing?
The Create-React-App is basically React with an integrated build system. It acts like a good boilerplate, so we don't need to set up Webpack, Babel, and other dependent packages to run React. Other than that, if you require extra functionalities such as routing, server-side rendering, and so on, you just need to add packages on top of Create-React-App. On the other hand, The Next.js is an open-source, lightweight full-stack React framework that comes bundled with an efficient build system, server-side rendering, routing, API routing, and many other awesome features that make the production environment easy.
10) How can you install and use Next.js?
There are mainly two ways to install and run Next.js on your system. If you're new to Next.js, we recommend that you make sure that your development environment is ready. Next.js is a React framework, and it requires Node.js to be installed on your system. If you don't have Node.js installed, you can install it from here: https://www.javatpoint.com/install-nodejs. Next.js requires Node.js version 10.13 or later. You should also have your text editor and terminal.
System Requirement for Next.js
The simplest way to install Next.js
Manual Installation and Setup of Next.js
The above script specifies the different stages of developing an application:
Next.js is built around the concept of pages. A page is a React Component exported from a .js, .jsx, .ts, or .tsx file in the pages directory. Pages are associated with a route based on their filename. For example, pages/about.js is mapped to /about. You can even add dynamic route parameters with the filename.
11) How can you disable the etag generation in Next.js?
Generally, we use the app.disable('etag') syntax to disable the etag generation in Next.js. But, this may not work for all static contents. So, we should use the following syntax to disable the etag for all static contents.
12) How can you configure the build-id in Next.js?
To configure the build-id in Next.js, we must configure a static ID between our builds. So, we have to provide the "generateBuildId" function with the following configuration.
13) How can you create a page directory inside your project?
To create a page directory inside our project we have to populate the ./pages/index.js with the following contents:
To start developing our application, we have to run the npm run dev or yarn dev command. This will start the development server on http://localhost:3000. Now we can visit the localhost: http://localhost:3000 to view our application.
14) Give an example to demonstrate how to create a custom error page in Next.js?
We can create our custom error page by defining a _error.js in the pages folder. See the following example:
15) What do you understand by code splitting in Next.js?
Generally, code splitting is one of the most compelling features of webpack. This feature facilitates us to split our code into various bundles, which can be loaded only on-demand or in parallel. This is mainly used to achieve the smaller bundles and facilitates us to control resource load prioritization which finally has a great impact on the load time.
There are mainly three approaches to code splitting:
It is mainly used to enable pages that can never load unnecessary code.
16) How can you enable AMP in Next.js?
This is an important question and is asked in many Next.js interview questions. There are two ways to enable AMP in Next.js.
AMP-First Pages: The AMP-First Pages are served to the primary traffic of the website as well as traffic generated from the search engine. Use the following syntax to implement AMP-first pages.
Hybrid AMP Pages: The Hybrid AMP pages allow the users to have coexisted AMP version of a traditional page so that the search engines can display the AMP version or the page in different mobile search results.
See the following example to understand how to implement the Hybrid AMP to pages:
17) Is it possible to host Next.js in a web server like Nginx?
Next.js is not as simple as static html files. It requires an application server that runs Node.js to deploy and run a Next.js application. Here, we get requests that have to be processed on the server.