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

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "By wrapping the App component, the BrowserRouter component enriches it with routing capabilities."

A block of code is set as follows:

class Catalog extends React.Component {
  constructor() {
    super();

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

import { BrowserRouter } from 'react-router-dom'
ReactDOM.render(
  <BrowserRouter>
    <App />
  </BrowserRouter>
  , document.getElementById('root'));

Any command-line input or output is written as follows:

create-react-app --version

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Now we need to create a view to display the Catalog component or the About page."

Activity: These are scenario-based activities that will let you practically apply what you've learned over the course of a complete section. They are typically in the context of a real-world problem or situation.