Lesson 11 / 25

The res Object

Send text, JSON, status codes and redirects with the res object and avoid sending twice.

send, json, status, redirect

res.send() sends text/HTML/buffer, res.json() sends JSON, res.status(code) sets the HTTP status, res.redirect(url) sends a 3xx redirect.

Chaining

Most res methods return res, so they chain naturally.

app.post('/items', (req, res) => {
  res.status(201).json({ id: 1, name: 'Widget' });
});

app.get('/old-path', (req, res) => {
  res.redirect(301, '/new-path');
});

Respond exactly once

Calling res.send/res.json twice on one request throws ERR_HTTP_HEADERS_SENT — always return after sending inside a branch.