Book Image

React Key Concepts

By : Maximilian Schwarzmüller
Book Image

React Key Concepts

By: Maximilian Schwarzmüller

Overview of this book

As the most popular JavaScript library for building modern, interactive user interfaces, React is an in-demand framework that’ll bring real value to your career or next project. But like any technology, learning React can be tricky, and finding the right teacher can make things a whole lot easier. Maximilian Schwarzmüller is a bestselling instructor who has helped over two million students worldwide learn how to code, and his latest React video course (React — The Complete Guide) has over six hundred thousand students on Udemy. Max has written this quick-start reference to help you get to grips with the world of React programming. Simple explanations, relevant examples, and a clear, concise approach make this fast-paced guide the ideal resource for busy developers. This book distills the core concepts of React and draws together its key features with neat summaries, thus perfectly complementing other in-depth teaching resources. So, whether you've just finished Max’s React video course and are looking for a handy reference tool, or you've been using a variety of other learning materials and now need a single study guide to bring everything together, this is the ideal companion to support you through your next React projects. Plus, it's fully up to date for React 18, so you can be sure you’re ready to go with the latest version.
Table of Contents (16 chapters)

7. Portals & Refs

Activity 7.1: Extract User Input Values

In this activity, you have to add logic to an existing React component to extract values from a form. The form contains an input field and a drop-down menu and you should make sure that, upon form submission, both values are read and, for the purpose of this dummy app, output to the browser console.

Use your knowledge about refs and uncontrolled components to implement a solution without using React state.


You can find the starting code for this activity at When downloading this code, you'll always download the entire repository. Make sure to then navigate to the subfolder with the starting code (activities/practice-1/starting-code in this case) to use the right code snapshot.

After downloading the code and running npm install in the project folder (to install all the required dependencies), the solution steps are as follows:

  1. Inside the Form component, create two...