res.status for status codes in Express - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What does res.status(404).send('Not Found') do?

In an Express app, what is the effect of calling res.status(404).send('Not Found') inside a route handler?

Express

app.get('/item', (req, res) => {
  res.status(404).send('Not Found');
});

A Sends a response with HTTP status 200 and body 'Not Found'.

B Throws an error and crashes the server.

C Sends a response with HTTP status 404 but no body.

D Sends a response with HTTP status 404 and body 'Not Found'.

💡 Hint

Think about what res.status() sets and what send() does.

The res.status(404) sets the HTTP status code to 404. The send('Not Found') sends the response body with that status. So the client gets a 404 status and the text 'Not Found'.

📝 Syntax

intermediate

Which option correctly sets status 201 and sends JSON data?

Choose the correct Express code to send a 201 status with JSON {"success": true}.

A res.status(201).sendJson({success: true});

B res.send(201).json({success: true});

C res.status(201).json({success: true});

D res.status = 201; res.json({success: true});

💡 Hint

Remember the correct method to set status and send JSON.

res.status(201) sets the status code. json() sends JSON data. Option C uses both correctly.

🔧 Debug

advanced

Why does res.status(500).send() send a blank response?

In Express, what happens if you call res.status(500).send() without any argument?

Express

app.get('/error', (req, res) => {
  res.status(500).send();
});

A It throws a TypeError because send() needs an argument.

B It sends a 500 status with an empty body.

C It sends a 500 status with the default error message.

D It sends a 200 status with an empty body.

💡 Hint

Check what happens when send() is called with no argument.

Calling send() without arguments sends an empty response body but keeps the status code set by res.status(500).

❓ state_output

advanced

What is the status code after res.status(200).status(404).send('Oops')?

Consider this Express code snippet:

res.status(200).status(404).send('Oops');

What status code will the client receive?

A 404

B 200

C 500

D It causes an error and no response is sent.

💡 Hint

Think about method chaining and which status code is last set.

The last status(404) call overrides the previous status(200). So the response status is 404.

🧠 Conceptual

expert

Which status code is most appropriate for a successful resource creation?

In REST APIs using Express, which HTTP status code should you set with res.status() when a new resource is successfully created?

A 201

B 200

C 204

D 400

💡 Hint

Think about the standard HTTP codes for resource creation.

Status 201 means 'Created' and is the standard code to indicate successful creation of a resource.