Building a REST API with Node.js

In this tutorial, we will build a RESTful API using Node.js and Express. A RESTful API is an application programming interface that follows the principles of REST (Representational State Transfer). We will use Express, a Node.js web application framework, to create our API.

Installing Node.js

First, you need to install Node.js on your system. You can download Node.js from the official website.

npm init -y
npm install express

We create an index.js file and add the following code:

const express = require("express");
const app = express();
const port = 3000;

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

app.listen(port, () => {
  console.log(`Server is running on http://localhost:${port}`);
});

To run the application, execute the following command:

node index.js

Now you can access your application at http://localhost:3000.

Creating API Routes

Let’s create some routes for our API. For example, a route to get a list of users and another route to get a user by their ID.

app.get("/api/users", (req, res) => {
  res.json([
    { id: 1, name: "Alice" },
    { id: 2, name: "Bob" },
  ]);
});

app.get("/api/users/:id", (req, res) => {
  const id = req.params.id;
  res.json({ id, name: "Alice" });
});

Now you can access the users API at http://localhost:3000/api/users and http://localhost:3000/api/users/1.

Conclusion

In this tutorial, we have built a RESTful API using Node.js and Express. You can add more routes and functionality to your API as needed. Have fun building your API!

I hope this tutorial has been helpful. If you have any questions, feel free to leave a comment.