Express

Express is a Node.js web application framework that provides a robust set of features for web and mobile applications.

Installation

From backend folder, use npm to install express:

npm install express

You will also need to install CORS.

npm install cors

note

Your browser won't let you make requests to a server that is not on the same domain. CORS is a node.js package for providing a Connect/Express middleware that can be used to enable CORS with various options.

Create a GET route

Create a file called index.mjs in the backend folder. This file will contain the code for your server.

import express from "express";
import cors from "cors";

const app = express();
const port = 5050;

app.use(cors());

app.get("/", (req, res) => {
  res.send("Hello World!");
});

app.listen(port, () => {
  console.log(`Example app listening at http://localhost:${port}`);
});

Run the server

From the backend folder, run the following command:

node index.mjs

You should see the following message in the console:

Example app listening at http://localhost:3000

tip

You can also use nodemon to run the server. This will automatically restart the server when you make changes to the code.

nodemon index.mjs