Node.js Modules

Spread the love

What is a Module in Node.js?

A set of functions that you want to include in your application.

Built-in Modules

Node.js has a set of built-in modules that you can use without any further installation.
Examples:

assert	Provides a set of assertion tests
buffer	To handle binary data
child_process	To run a child process
cluster	To spla singlit e Node process into multiple processes
crypto	To handle OpenSSL cryptographic functions
dgram	Provides implementation of UDP data gram sockets
dns	To do DNS lookup and name resolution functions
domain	Deprecated. To handle unhanded errors
events	To handle events
fs	To handle the file system
http	To make Node.js act as an HTTP server
https	To make Node.js act as an HTTPS server.
net	To create servers and clients
os	Provides information about the operation system
path	To handle file paths
punycode	Deprecated. A character encoding scheme
querystring	To handle URL query strings
readline	To handle readable streams one line at the time
stream	To handle streaming data
string_decoder	To decode buffer objects into strings
timers	To execute a function after a given number of milliseconds
tls	To implement TLS and SSL protocols
tty	Provides classes used by a text terminal
url	To parse URL strings
util	To access utility functions
v8	To access information about V8 (the JavaScript engine)
vm	To compile JavaScript code in a virtual machine
zlib	To compress or decompress files

How to Include Modules

To include a module, use the require() function with the name of the module
Examples

var http = require(‘http‘);

var timers= require(‘timers‘);

Create Your Own Modules

You can create your own modules, and easily include them in your applications.

See the following example.

mydate.js

—————————————————————————————————

exports.myDateTime=function(){
return Date();
}

exports.myTime=function(){
var date=new Date();
return date.getHours()+”:”+date.getMinutes();

}

exports.myYear=function(){
var date=new Date();
return date.getFullYear();
}

exports.myMonth=function(){
var date=new Date();
return (date.getMonth()+1);
}

index.js

————————————————————————————————–

var http=require(‘http’);
var mydate=require(‘./mydate’);//here iclude my created module

http.createServer(

function (req,res){
var today=mydate.myDateTime();
res.write(“Today is:”+today+”\n”);
var now=mydate.myTime();
res.write(“Now time is:”+now+”\n”);
var year=mydate.myYear();
res.write(“Year is:”+year+”\n”);

var month=mydate.myMonth();
res.write(“Month is:”+month+”\n”);
res.end();
}

).listen(8080);