Preface

Hello there! The Complete ReactJS Interview Guide is a book that will assist developers in getting ready for a React interview in order to land a job. You will discover several tactics and ideas to ace your upcoming React interview in this book.

This book will cover all the different steps when getting ready for a React interview, starting from the preparation phase and going all the way to building some real-world projects, where you will gain insight to help you complete the take-home programming assignments in the final chapters.

The React ecosystem is quite vast, so many topics will be discussed throughout so that you get a fairly broad understanding of many of the most talked-about features and concepts related to React. Some of the topics we will touch on include state, components, Hooks, and testing.

Who this book is for

Aspiring web developers, programmers, and React developers can gain practical knowledge on how to perform well in React interviews.

The three main personas who are the target audience of this book are as follows:

• Aspiring web developers: Developers who are new to programming and want to learn React from the ground up and wish to crack React interviews
• Programmers: Any programmer who wishes to expand their knowledge and skillset by learning about React and how to do well in interviews
• React developers: They will gain insight into upgrading their existing React skills, leading to further career progression as a React developer

What this book covers

Chapter 1, Brace Yourself for Interview Preparation, provides an introduction to how to best prepare for upcoming React-based interviews. It will cover preparing a résumé and cover letter, as well as tips on creating a GitHub profile or website. The chapter will also discuss how to find work on job boards and LinkedIn and how meetups and referrals can assist with job searches. Additional interview tips are recommended.

Chapter 2, Understanding ReactJS Fundamentals and Its Major Features, provides an overview of some of the core fundamentals of ReactJS, covering many of the main topics, which include the JSX language, state, and props, as well as class and functional components. The chapter will also explain event handling, the virtual DOM, data flow, the context API, and how to do server-side rendering.

Chapter 3, Hooks: Bring State and Other Features into Functional Components, provides an overview of the various hooks that are available to use in ReactJS alongside their use cases. At the end of the chapter, you will learn how to create your own custom hooks.

Chapter 4, Handling Routing and Internationalization, provides an overview of how to handle routing and internationalization. The chapter primarily covers the React Router library and how to do page routing within a React application. Numerous topics are covered, including routes, links, parameters, translation, and how to pass arguments and placeholders.

Chapter 5, Advanced Concepts of ReactJS, provides an overview of advanced concepts in ReactJS. This chapter goes into detail on how to use error boundaries, portals, debugging with the Profiler API, strict mode, and concurrent rendering. The chapter also covers code splitting in addition to using React when in a mobile environment.

Chapter 6, Redux: The Best State Management Solution, provides an overview of how we can use Redux inside of our React applications. The chapter discusses the Flux pattern and Redux, going over their core principles and how to use them to manage the state within an application. With the help of this chapter, you will also learn about Redux middleware, Saga, Thunk, DevTools, and testing.

Chapter 7, Different Approaches to Apply CSS in ReactJS, provides an overview of how we can incorporate CSS into our React applications. There are different implementations, such as using processors, CSS Modules, CSS-in-JS, and styled-components, all of which will be discussed.

Chapter 8, Testing and Debugging the React Application, provides an overview of the concepts of testing and debugging within a React application. The chapter will go into detail on using React testing helpers, as well as the steps to perform a setup and teardown. Setups and teardowns are done while writing tests because we frequently need to do configurations before the tests run, and also at the end after the tests have finished running.

As well as data fetching and mocking, you will also gain knowledge on how to create events and timers and how we can use the React DevTools to do our debugging and analysis.

Chapter 9, Rapid Development with Next.js, Gatsby, and Remix Frameworks, provides an overview of how it's possible to use React to build full stack applications. The chapter aims to give an insight into using frameworks such as Next.js, Remix, and Gatshy to develop their React applications. You will also learn how to do static site generation, server-side rendering, and add page metadata.

Chapter 10, Cracking Any Real-World Programming Task, provides an overview of how to prepare for upcoming programming take-home assignments or code challenges when going through an interview process. You will learn how to set up a development environment and about the right tools and templates for a project. It is also important for you to learn about the benefits of choosing the right architecture, the reasons for good code testing, and how to share the project on GitHub, which will be covered here.

Chapter 11, Building an App Based on React, Redux, Styled Components, and the Firebase Backend, provides an overview of how to build a React application that connects to a Firebase database. The chapter will go into detail about how to best plan the architecture for the application, how to create the business logic and presentation layer, and how to set up the testing layer. When everything has been completed, you will learn how to deploy the application to GitHub so that it can be viewed publicly online.

Chapter 12, Building an App Based on NextJS Toolkit, Authentication, SWR, GraphQL, and Deployment, provides an overview of how to build a React application that has an authentication layer. The chapter will go into detail about how to best plan the architecture for the application and, in this case, use SWR and GraphQL, followed by the creation of the business logic and presentation layer, and setting up the testing layer. When everything has been completed, you will learn how to deploy the application to GitHub so that it can be viewed publicly online.

To get the most out of this book

Readers should have knowledge of JavaScript or any similar programming languages, frameworks, or libraries. Prior knowledge of React is welcome but not required. Having a basic understanding of programming concepts and methodologies is recommended.

Software/hardware covered in the book

Operating system requirements

React 18

Windows, macOS, or Linux

TypeScript 3.7

ECMAScript 11

Readers should have a programming setup with an integrated development environment (IDE), a command-line interface (CLI) application, and any tools, frameworks, libraries, or packages installed, such as NodeJS, npm, and Next.js.

If you are using the digital version of this book, we advise you to type the code yourself or access the code from the book's GitHub repository (a link is available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.

Download the example code files

You can download the example code files for this book from GitHub at https://github.com/PacktPublishing/React-Interview-Guide. If there's an update to the code, it will be updated in the GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file...