Book Image

React and React Native - Third Edition

By : Adam Boduch, Roy Derks
Book Image

React and React Native - Third Edition

By: Adam Boduch, Roy Derks

Overview of this book

React and React Native, Facebook’s innovative User Interface (UI) libraries, are designed to help you build robust cross-platform web and mobile applications. This updated third edition is improved and updated to cover the latest version of React. The book particularly focuses on the latest developments in the React ecosystem, such as modern Hook implementations, code splitting using lazy components and Suspense, user interface framework components using Material-UI, and Apollo. In terms of React Native, the book has been updated to version 0.62 and demonstrates how to apply native UI components for your existing mobile apps using NativeBase. You will begin by learning about the essential building blocks of React components. Next, you’ll progress to working with higher-level functionalities in application development, before putting this knowledge to use by developing user interface components for the web and for native platforms. In the concluding chapters, you’ll learn how to bring your application together with a robust data architecture. By the end of this book, you’ll be able to build React applications for the web and React Native applications for multiple mobile platforms.
Table of Contents (33 chapters)
Section 1: React
Section 2: React Native
Section 3: React Architecture

Maintaining state using Hooks

The first React Hook API that we'll look at is called useState(), which enables your functional React components to be stateful. Before Hooks were introduced to React, our only option for creating stateful components was to use a class so that we could access the setState() method. In this section, you'll learn how to initialize state values, and how to change the state of a component using Hooks.

Initial state values

When our components are first rendered, they probably expect some state values to be set. This is called the initial state of the component, and we can use the useState() Hook to set the initial state. Let's take a look at an example:

import React, { Fragment, useState } from 'react';

export default function App() {
const [name] = useState('Adam');
const [age] = useState(35);

return (
<p>My name is {name}</p>
<p>My age is {age}</p>