res.send for general responses in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does res.send() do in Express?

res.send() sends a response back to the client. It can send strings, objects, or buffers as the HTTP response body.

beginner

Can res.send() send JSON objects directly?

Yes, if you pass an object to res.send(), Express converts it to JSON and sets the Content-Type header to application/json.

intermediate

What happens if you call res.send() multiple times in one request?

Only the first call to res.send() sends the response. Subsequent calls are ignored or cause errors because the response is already sent.

intermediate

How does res.send() differ from res.json()?

res.send() can send any type of response (string, buffer, object), while res.json() specifically sends JSON and sets the Content-Type header to application/json.

beginner

What is a simple example of using res.send() to send a text response?

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

This sends the text 'Hello, friend!' to the browser.

What type of data can res.send() send in Express?

A Only HTML files

B Only strings

C Only JSON objects

D Strings, objects, buffers

res.send() can send strings, objects (which it converts to JSON), and buffers as responses.

If you pass an object to res.send(), what does Express do?

A Converts it to JSON and sets Content-Type to application/json

B Throws an error

C Sends it as plain text

D Ignores the object and sends nothing

Express automatically converts objects to JSON and sets the correct header.

What happens if you call res.send() twice in the same route handler?

A Both responses are sent one after another

B The second call overwrites the first response

C Only the first call sends a response; the second is ignored or causes an error

D Express queues both responses and sends them together

Once the response is sent, you cannot send another one for the same request.

Which method is more specific for sending JSON responses?

A res.render()

B res.json()

C res.send()

D res.redirect()

res.json() is designed specifically to send JSON responses.

What header does Express set automatically when sending an object with res.send()?

A Content-Type: application/json

B Content-Type: text/html

C Content-Type: text/plain

D Content-Type: application/xml

Express sets the Content-Type header to application/json when sending objects.

Explain how res.send() works in Express and what types of data it can send.

Think about what happens when you pass different data types to res.send()

Describe the difference between res.send() and res.json() in Express.

Consider when you want to send JSON specifically versus other data