[Solved] You have this Express.js route handler:app.get('/users/:id', (req, res) => { const users = {1: 'Alice', 2: 'Bob'};... });What is the problem with this code when a user is not found? | Rest API

Rest API - HTTP Status Codes

You have this Express.js route handler:

app.get('/users/:id', (req, res) => {
  const users = {1: 'Alice', 2: 'Bob'};
  const user = users[req.params.id];
  if (!user) {
    res.status(404);
  }
  res.send(user);
});

What is the problem with this code when a user is not found?

AIt correctly sends a 404 status with no body.

BIt sends a 404 status but still sends undefined as response body.

CIt throws a syntax error due to missing semicolon.

DIt sends a 500 Internal Server Error automatically.

Step-by-Step Solution

Solution:

Step 1: Analyze response when user not found
res.status(404) sets status but does not end response or send body.
Step 2: Check what res.send(user) does
res.status(404) sets the status, but execution continues to res.send(undefined), which sends the string 'undefined' as body with 404 status.
Final Answer:
It sends a 404 status but still sends undefined as response body. -> Option B
Quick Check:
Missing res.send after status causes wrong response [OK]

Quick Trick: Always send response body or end response after setting status [OK]

Common Mistakes:

Setting status without sending response body
Assuming status alone ends response
Not checking for undefined response body

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More Rest API Quizzes

You have this Express.js route handler:

Step 1: Analyze response when user not found

Step 2: Check what res.send(user) does

Final Answer:

Quick Check:

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