Build HTTP APIs with routing, middleware, validation, controllers, and error handling.
Lessons
Match each REST outcome to the most accurate HTTP status.
Choosing Status Codes 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());
const lessons = [];
app.get('/api/v1/lessons', (req, res) => res.json({ data: lessons }));
app.post('/api/v1/lessons', (req, res) => {
const lesson = { id: lessons.length + 1, ...req.body };
lessons.push(lesson);
res.status(201).json({ data: lesson });
});
app.put('/api/v1/lessons/:id', (req, res) => res.json({ data: { id: req.params.id, ...req.body } }));
app.delete('/api/v1/lessons/:id', (req, res) => res.status(204).end());
app.listen(3000);Practice the Choosing Status Codes example in a small scratch file, then explain what changed and why.