Hello world application using nodejs and express
In this tutorial, we will learn how to display hello world in our application using nodejs and express, We will know about nodejs. Nodejs is open source framework it used the javascript server and it is run on different os like as Windows, Linux, Unix, and Mac, etc. so first we will check the node is intall or no in our system, if no in our system, then after we will goto follow below Url and install node.js.
How to install and download nodejs and npm for window os
Let’s go and follow below step for how to display hello world in our application using nodejs and exress.js.
Step 1: Create Application Directory.
First, we will open the command prompt and create the application directory. for this you can follow below command.
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mkdir myapp cd myapp |
Step 2: Create a application using npm init
The “npm init” command through we can create a new package.json file in our application directory. when we build new app that time we use this command. Node.js will need to have a package.json file because includes the application related packages and applications data.
Here below command help to initialization our application.
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npm init This utility will walk you through creating a package.json file. It only covers the most common items, and tries to guess sensible defaults. See `npm help json` for definitive documentation on these fields and exactly what they do. Use `npm install <pkg>` afterwards to install a package and save it as a dependency in the package.json file. Press ^C at any time to quit. package name: (myapp) myapp version: (1.0.0) description: myapp entry point: (index.js) test command: git repository: keywords: author: license: (ISC) About to write to E:\test_mac\myapp\package.json: { "name": "myapp", "version": "1.0.0", "description": "myapp", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "author": "", "license": "ISC" } Is this OK? (yes) yes |
Step 3: Install Express Package
Expess.js is free and open-source framework and it’s web application framework for Node.js. we can manage routes, create restful api, handle the request and response and also create MVC structure using the express.js. Npm stands for node package manager. npm help to installing node packages and manage the types of dependencies.
Here below command help to install express package.
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npm install express --save |
Step 4: Create New File and Save
First, we will take a new file and paste follow below code in our file and save as app.js.
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var express = require('express'); var app = express(); app.get('/', function (req, res) { res.send('Hello World!'); }); app.listen(3000, function () { console.log('application listening on port 3000!'); }); |
Step 5: Run Our Application
Finally, We will run our application using the follow below command.
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node app.js |