Build HTTP APIs with routing, middleware, validation, controllers, and error handling.
Lessons
Use the application object to configure routes, settings, and middleware.
The Express app Object is easiest to learn by reading the example, changing it, and observing the result.
import express from 'express';
const app = express();
app.use(express.json());
app.get('/api/lessons', (req, res) => {
res.json([{ slug: 'express-routing', title: 'Express Routing' }]);
});
app.post('/api/lessons', (req, res) => {
res.status(201).json({ created: true, title: req.body.title });
});
app.listen(process.env.PORT || 3000);Practice the The Express app Object example in a small scratch file, then explain what changed and why.