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, path names, dummy URLs, user input, and Twitter handles. Here is an example: "A user looking for a music player with the ability to show liked or disliked songs will end up using the <music-player> component rather than something else." 

A block of code is set as follows:

class myClass {
 constructor() {
 // do stuff
 }
}

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

class HelloWorld extends HTMLElement {
  constructor() {
    super();

    // do magic here
    this.innerText = 'Hello World';
  }
}

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

$ py -m http.server

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: "Enter your NPM package name and click on the Publish button."