What is Express.js and how do I get started with it?

What is Express.js and how do I get started with it?

Express.js is a web application framework for Node.js, designed for building web applications and APIs. To get started, you can install it using npm and create a simple server.

Can you show me a basic example of an Express.js server?

Sure! Here's a simple example:

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

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

app.listen(3000, () => {
  console.log('Server is running on http://localhost:3000');
});

What are some common middleware used in Express.js?

Common middleware includes body-parser for parsing request bodies, morgan for logging requests, and cors for enabling CORS.

How do I handle errors in Express.js?

You can handle errors by defining an error-handling middleware function. It takes four arguments: err, req, res, and next. Here's an example:

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).send('Something broke!');
});