To install express.js using npm, run the following command.
npm install express
To install it globally, run the above command with
-g option. g for global.
npm install -g express
Once express.js is installed, you can import express.js into your node project using require statement.
var express = require('express')
express variable holds the reference to the express.js package.
If you do not install express.js prior to using it in your Node.js project, you will get an error as below: