Create a REST API with Node.js and Express
Introduction
REST (Representational State Transfer) APIs are used to connect frontend and backend applications. With Node.js and Express, you can create REST APIs quickly and efficiently. In this tutorial, we will create a simple API to manage user data (Create, Read, Update, Delete).
Steps
1. Project Preparation
a. Make sure you have Node.js installed on your computer. Check with::
node -v npm -v
b. Create a new project folder and go into it:
mkdir rest-api-node cd rest-api-node
c. Initialize the project:
npm init -y
d. Instal Express:
npm install express
2. Project Structure
Create a folder structure like this:
rest-api-node/ | |--- index.js # Main file |--- package.json # Config File
3. Create API
Open index.js file and add the following code:
a. Setup Server
const express = require('express');
const app = express();
const port = 3000;
// Middleware for parsing JSON
app.use(express.json());
// Root Endpoint
app.get('/', (req, res) => {
res.send('Welcome to the User API!');
});
// Run the server
app.listen(port, () => {
console.log(`Server berjalan di http://localhost:${port}`);
});
Run your server with the command:
node index.js
Visit http://localhost:3000/ to see the output "Welcome to the User API!".
b. Add Data Dummy
Add dummy data above the endpoint code:
let users = [
{ id: 1, name: "John Doe", email: "[email protected]" },
{ id: 2, name: "Jane Doe", email: "[email protected]" }
];
c. Endpoint CRUD
Add the following endpoints:
- Get All Users
app.get('/users', (req, res) => {
res.json(users);
});
- Get User By ID
app.get('/users/:id', (req, res) => {
const user = users.find(u => u.id === parseInt(req.params.id));
if (!user) return res.status(404).send('User not found');
res.json(user);
});
- Adding New Users
app.post('/users', (req, res) => {
const newUser = {
id: users.length + 1,
name: req.body.name,
email: req.body.email
};
users.push(newUser);
res.status(201).json(newUser);
});
- Updating Users
app.put('/users/:id', (req, res) => {
const user = users.find(u => u.id === parseInt(req.params.id));
if (!user) return res.status(404).send('User not found');
user.name = req.body.name;
user.email = req.body.email;
res.json(user);
});
- Deleting Users
app.delete('/users/:id', (req, res) => {
const userIndex = users.findIndex(u => u.id === parseInt(req.params.id));
if (userIndex === -1) return res.status(404).send('User not found');
const deletedUser = users.splice(userIndex, 1);
res.json(deletedUser);
});
API Testing
Use Postman or cURL to test the endpoints:
1. GET /users
Get a list of users.
2. GET /users/:id
Get user details by ID.
3. POST /users
Add a new user with a JSON payload like:
{ "name": "Alice", "email": "[email protected]" }
4. PUT /users/:id
Update a user by ID with a JSON payload.
5. DELETE /users/:id
Delete a user by ID.
Conclusion
You have successfully created a simple REST API with Node.js and Express. For further development, you can add a database (such as MongoDB or MySQL) and authentication features.
