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 extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "The element can be as simple as h1, a div element, or it can be an artificial element that does things differently."

A block of code is set as follows:

fetch('/giveMeANumber').then(res => { 
  ReactDOM.render(<Title />, rootEl) 
}) 

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

let c = 3
function add(a, b) {
  console.log(a, b)
  return a + b + c
}

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: "This flag can be used to decide if the UI should display the Logout or Login button."

Tips or Important Notes

Appear like this.