In this article, we will see the introduction to Node.js Modules. Node.js modules provide a way to re-use code in your Node.js application. Node.js modules to be the same as JavaScript libraries. Node.js provide set of built-in modules which you can use without any further installation. like assert, crypto, fs, http, https, path, url, etc.
Please check more details or modules on Built-in Module in Node js.
for include module use the require()
function with the name of the module.
var http = require('http');
Now, your application has access to the HTTP module, and is able to create a server.
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.end('Websolutionstuff !!');
}).listen(3000);
You can create your custom modules and you can easily include in your applications.
In below example creates a module that returns a date and time object.
exports.custom_DateTime = function () {
return Date();
};
Use the exports
keyword to make properties and methods available outside the module file.
Save the code above in a file called "custom_module.js".
Now, you can include and use the module in any of your Node.js files.
var http = require('http');
var dt = require('./custom_module');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write("Date and Time : " + dt.custom_DateTime());
res.end();
}).listen(3000);
Notice that the module is located in the same folder as the Node.js file. or add path of module file.
Save above code in "custom_module_demo.js" file. and run below command in your terminal.
node custom_module_demo.js
Output :
Date and Time : Wed Sep 08 2021 20:05:04
You might also like: