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: "Let's attach a page heading to the body with the <h1> tag."

A block of code is set as follows:

// generate random number
var min = 1 ;
var max = 10 ;
var a = Math.floor( Math.random() * (max + 1 - min) ) + min ;
// set random number to message
msg.payload = a;
// return message
return msg;

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

$ node --version
v12.18.1
$ npm –version
6.14.5

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: "After selecting the name and payment plan, click the Select Region button."

Tips or important notes

Appear like this.