Conventions used

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: "The http object encapsulates the HTTP protocol, and its http.createServer method creates a whole web server, listening on the port specified in the listen method."

A block of code is set as follows:

var http = require('http'); 
http.createServer(function (req, res) { 
  res.writeHead(200, {'Content-Type': 'text/plain'}); 
  res.end('Hello World\n'); 
}).listen(8124, "127.0.0.1"); 
console.log('Server running at http://127.0.0.1:8124/'); 

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

 if (urlP.query['n']) { 
    fibonacciAsync(urlP.query['n'], fibo => {
        res.end('Fibonacci '+ urlP.query['n'] +'='+ fibo);
    });
  } else { 

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

$ node --version
v8.9.1  

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: "In the Start menu, enter PowerShell in the applications search box."

Warnings or important notes appear like this.

Tips and tricks appear like this.