req.method and req.url in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to log the HTTP method of the request.

Express

app.use((req, res) => {
  console.log(req.[1]);
  res.end();
});

Drag options to blanks, or click blank then click option'

Amethod

Burl

Cbody

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.url instead of req.method

Trying to access req.body without middleware

The req.method property contains the HTTP method (GET, POST, etc.) of the request.

2fill in blank

medium

Complete the code to log the URL path of the request.

Express

app.use((req, res) => {
  console.log(req.[1]);
  res.end();
});

Drag options to blanks, or click blank then click option'

Apath

Bmethod

Curl

Dquery

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.method instead of req.url

Trying to use req.path which is not always available

The req.url property contains the URL path and query string of the request.

3fill in blank

hard

Fix the error in the code to correctly check if the request method is POST.

Express

app.use((req, res) => {
  if (req.[1] === 'POST') {
    res.end('Got a POST request');
  } else {
    res.end('Not a POST request');
  }
});

Drag options to blanks, or click blank then click option'

Aheaders

Bbody

Curl

Dmethod

Attempts:

3 left

💡 Hint

Common Mistakes

Checking req.url instead of req.method

Using lowercase 'post' instead of uppercase 'POST'

To check the HTTP method, use req.method. Comparing req.url or others will not work.

4fill in blank

hard

Fill both blanks to log the method and URL of the request.

Express

app.use((req, res) => {
  console.log('Method:', req.[1]);
  console.log('URL:', req.[2]);
  res.end();
});

Drag options to blanks, or click blank then click option'

Amethod

Burl

Cbody

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping method and url properties

Using req.body or req.headers instead

Use req.method for the HTTP method and req.url for the URL path.

5fill in blank

hard

Fill all three blanks to respond differently based on method and log the URL.

Express

app.use((req, res) => {
  if (req.[1] === 'GET') {
    res.end('GET request received');
  } else if (req.[2] === 'POST') {
    res.end('POST request received');
  } else {
    res.end('Other request');
  }
  console.log('URL:', req.[3]);
});

Drag options to blanks, or click blank then click option'

Aurl

Bmethod

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.url in the if conditions

Logging req.method instead of req.url

Check req.method for the HTTP method in both conditions and log req.url for the URL.

Practice

1. What does req.method represent in an Express request?

easy

A. The HTTP method used by the client (e.g., GET, POST)

B. The full URL including domain name

C. The IP address of the client

D. The server's response status code

Solution

1. Step 1: Understand the purpose of req.method

   req.method holds the HTTP method used by the client to make the request, such as GET, POST, PUT, DELETE.

2. Step 2: Differentiate from other request properties

   req.url gives the path and query, IP address is separate, and response status is not part of the request object.

3. Final Answer:

   The HTTP method used by the client (e.g., GET, POST) -> Option A

4. Quick Check:

   req.method = HTTP method [OK]

Hint: Remember: method means action type like GET or POST [OK]

Common Mistakes:

• Confusing req.method with req.url
• Thinking req.method gives client IP
• Assuming req.method is server response code

2. Which of the following is the correct way to check if a request is a POST method in Express?

easy

A. if (req.url === 'POST')

B. if (req.url === '/post')

C. if (req.method = 'POST')

D. if (req.method === 'POST')

Solution

1. Step 1: Identify the property holding HTTP method

   The HTTP method is stored in req.method, so we compare it to the string 'POST'.

2. Step 2: Check syntax correctness

   if (req.method === 'POST') uses strict equality (===) to compare req.method to 'POST', which is correct. if (req.method = 'POST') uses assignment (=) which is wrong.

3. Final Answer:

   if (req.method === 'POST') -> Option D

4. Quick Check:

   Check req.method with === 'POST' [OK]

Hint: Use === to compare req.method with 'POST' string [OK]

Common Mistakes:

• Using assignment (=) instead of comparison (===)
• Checking req.url instead of req.method
• Comparing req.method to lowercase 'post'

3. Given this Express code snippet, what will be logged if a client sends a GET request to /home?user=123?

app.use((req, res, next) => {
  console.log(req.method);
  console.log(req.url);
  next();
});

medium

A. GET
/home?user=123

B. POST
/home?user=123

C. GET
/home

D. POST
/home

Solution

1. Step 1: Identify the HTTP method from the request

   The client sends a GET request, so req.method will be 'GET'.

2. Step 2: Identify the URL including query string

   req.url includes the path and query string, so it will be '/home?user=123'.

3. Final Answer:

   GET /home?user=123 -> Option A

4. Quick Check:

   req.method = GET, req.url includes query [OK]

Hint: req.url includes path plus query string [OK]

Common Mistakes:

• Ignoring query string in req.url
• Assuming req.method is POST by default
• Confusing req.url with just the path

4. What is wrong with this Express middleware code if it aims to log only POST requests?

app.use((req, res, next) => {
  if (req.method = 'POST') {
    console.log('POST request received');
  }
  next();
});

medium

A. Missing parentheses around req.method

B. Using assignment (=) instead of comparison (===) in the if condition

C. Logging message is incorrect

D. next() is called before the if condition

Solution

1. Step 1: Check the if condition syntax

   The condition uses = which assigns 'POST' to req.method instead of comparing it. This causes a bug.

2. Step 2: Identify correct comparison operator

   Use === to compare values in JavaScript, so the condition should be req.method === 'POST'.

3. Final Answer:

   Using assignment (=) instead of comparison (===) in the if condition -> Option B

4. Quick Check:

   Use === for comparison, not = [OK]

Hint: Use === to compare, not = which assigns [OK]

Common Mistakes:

• Using = instead of === in if condition
• Thinking next() must be before if
• Assuming parentheses needed around req.method

5. You want to create an Express middleware that logs a message only when the client requests the URL /api/data with a GET method. Which code snippet correctly implements this?

hard

A. app.use((req, res, next) => {
if (req.method === 'POST' && req.url === '/api/data') {
console.log('GET request to /api/data');
}
next();
});

B. app.use((req, res, next) => {
if (req.method = 'GET' || req.url === '/api/data') {
console.log('GET request to /api/data');
}
next();
});

C. app.use((req, res, next) => {
if (req.method === 'GET' && req.url === '/api/data') {
console.log('GET request to /api/data');
}
next();
});

D. app.use((req, res, next) => {
if (req.method === 'GET' && req.url === '/api') {
console.log('GET request to /api/data');
}
next();
});

Solution

1. Step 1: Check method and URL conditions

   The middleware should check if req.method is exactly 'GET' and req.url is exactly '/api/data'.

2. Step 2: Verify logical operators and syntax

   app.use((req, res, next) => { if (req.method === 'GET' && req.url === '/api/data') { console.log('GET request to /api/data'); } next(); }); uses strict equality (===) and logical AND (&&) correctly. app.use((req, res, next) => { if (req.method = 'GET' || req.url === '/api/data') { console.log('GET request to /api/data'); } next(); }); uses assignment (=) and OR (||) which is wrong. Options C and D check wrong method or URL.

3. Final Answer:

   app.use((req, res, next) => { if (req.method === 'GET' && req.url === '/api/data') { console.log('GET request to /api/data'); } next(); }); -> Option C

4. Quick Check:

   Check req.method === 'GET' AND req.url === '/api/data' [OK]

Hint: Use === and && to check method and exact URL [OK]

Common Mistakes:

• Using = instead of ===
• Using || instead of &&
• Checking wrong URL or method