Access HTTP header values from a request

You can access all the HTTP headers using the req.headers property:

app.get('/', (req, res) => {
  console.log(req.headers)
})

Use the req.get() or req.header() method to access one individual request header’s value:

app.get('/', (req, res) => {
  req.header('User-Agent')
})

Change any HTTP header value for a response

You can change any HTTP header value using res.set():

res.set('Content-Type', 'text/html')

There is a shortcut for the Content-Type header, however:

res.type('.html')
// => 'text/html'

res.type('html')
// => 'text/html'

res.type('json')
// => 'application/json'

res.type('application/json')
// => 'application/json'

res.type('png')
// => 'image/png'

Lessons in this unit:

0:	Introduction
1:	Introduction to Express
2:	Request parameters
3:	Send a response to the client
4:	Send a JSON response
5:	Manage cookies
6:	▶︎ Work with HTTP headers
7:	Handling redirects
8:	Routing
9:	Template engines
10:	Middleware
11:	Serving Static Assets with Express
12:	Send files to the client
13:	Sessions
14:	Validating and sanitizing input
15:	Handling form data
16:	Handling CORS
17:	HTTPS with a self-signed certificate
18:	HTTPS with Let's Encrypt
19:	Handling file uploads
20:	Build a REST API with MongoDB