Node.js Module

Node.js Module

In this tutorial, we will learn about Node.js module.

Node.js Module

You can consider Node.js module as java script library which has a set of function that you want to include in your application.

 Built-in Modules

Node.js has a set of build-in that you can include in your application with any further installation like http. 

Node.js  Include Modules

To include Node.js module we used require() function with parameter module name.

 var http = require('http');  

Now our application can use method which is in http module.

 const http = require('http');  
   
 const hostname = '127.0.0.1';  
 const port = 3000;  
   
 const server = http.createServer((req, res) => {  
  res.statusCode = 200;  
  res.setHeader('Content-Type', 'text/plain');  
  res.end('Hello World\n');  
 });  
   
 server.listen(port, hostname, () => {  
  console.log(`Server running at http://${hostname}:${port}/`);  
 });  
   

Create Your Own Modules

Create a file named mymodule.js and pasted the following code. This is a very simple module which has only one function myDateTime

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

We are using export keyword to make methods available outside the module file.

Include Your Own Module

 const http = require('http');  
 var dt = require('./mymodule');  
   
 const hostname = '127.0.0.1';  
 const port = 3000;  
   
 const server = http.createServer((req, res) => {  
  res.statusCode = 200;  
  res.setHeader('Content-Type', 'text/plain');  
  res.write("The date and time are currently: " + dt.myDateTime());  
  res.end();  
 });  
   
 server.listen(port, hostname, () => {  
  console.log(`Server running at http://${hostname}:${port}/`);  
 });  

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