Install Express.js

Firstly, you have to install the express framework globally to create web application using Node terminal. Use the following command to install express framework globally.

1. npm install -g express  

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Installing Express

Use the following command to install express:

1. npm install express --save   

The above command install express in node_module directory and create a directory named express inside the node_module. You should install some other important modules along with express. Following is the list:

• body-parser: This is a node.js middleware for handling JSON, Raw, Text and URL encoded form data.
• cookie-parser: It is used to parse Cookie header and populate req.cookies with an object keyed by the cookie names.
• multer: This is a node.js middleware for handling multipart/form-data.

1. npm install body-parser --save   

1. npm install cookie-parser --save   

1. npm install multer --save   

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Express.js App Example

Let's take a simple Express app example which starts a server and listen on a local port. It only responds to homepage. For every other path, it will respond with a 404 Not Found error.

1. File: express_example.js  

1. var express = require('express');  
2. var app = express();  
3. app.get('/', function (req, res) {  
4.    res.send('Welcome to JavaTpoint');  
5. })  
6. var server = app.listen(8000, function () {  
7. var host = server.address().address  
8.   var port = server.address().port  
9.  console.log("Example app listening at http://%s:%s", host, port)  
10. })  

Open http://127.0.0.1:8000/ in your browser to see the result.