ExpressJS Tutorial

Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications. It is an open source framework developed and maintained by the Node.js foundation.

What is Express.js?

Express provides a minimal interface to build our applications. It provides us the tools that are required to build our app. It is flexible as there are numerous modules available on npm, which can be directly plugged into Express.

Why Learn Express.js?

Express Framework unlike its competitors like Rails and Django, which have an opinionated way of building applications, has no "best way" to do something. It is very flexible and pluggable. It uses Pug, a template language for writing HTML templates.

How to Install Express.js?

Express requires Node.JS and NPM to be installed first. Different operating systems required different steps to install Node.js, please follow the provided methods according to your installed operating system.

Once node is installed, you can run the following npm command inside the Node project where package.json is residing.

npm install --save express

To make our development process a lot easier, we will install a tool from npm, nodemon. This tool restarts our server as soon as we make a change in any of our files, otherwise we need to restart the server manually after each file modification. To install nodemon, use the following command −

npm install -g nodemon

Example of Express.js Application

Once express set up is complete, we can start developing our first app using Express. Create a new file called index.js and type the following in it.

var express = require('express');
var app = express();

app.get('/', function(req, res){
   res.send("Hello world!");
});

app.listen(3000);

Save the file, go to your terminal and type the following.

nodemon index.js

This will start the server. To test this app, open your browser and go to http://localhost:3000 and a message will be displayed as in the following screenshot.

Prerequisites to Learn Express.js

Before proceeding with this tutorial, you should have a basic understanding of JavaScript. As we are going to develop web-based applications using Express.js and Node.js, it will be good if you have some understanding of other web technologies such as HTML, CSS, AJAX, etc.

Getting Started with Express.js

This tutorial is designed for software programmers who want to learn the Express.js and its architectural concepts from basics to advanced. This tutorial will give you enough understanding on all the necessary components of Express.js with suitable examples.

Considering NodeJS as base environement, before going deep into expressjs you should familiar with fundamentals of nodejs like environment setup, REPL terminal, NPM, Callbacks, Events, Objects, etc.

Express.js Jobs and Salary

Express.js. is a popular tool for almost any kind of project. After Learning Express.js you can get job on different job profiles.

Express.js Developer - Salary ranges in between 1.2 Lakhs to 12.6 Lakhs with an average annual salary of 5.7 Lakhs.
Express.js Backend Developer - Salary ranges in between 1.2 Lakhs to 11.0 Lakhs with an average annual salary of 4.7 Lakhs.

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