req.method and req.url in Express - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What does this Express handler log for a GET request to /home?

Consider this Express.js route handler:

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

What will be logged if a client sends a GET request to /home?

Express

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

A "GET /"

B "POST /home"

C "GET /home"

D "POST /"

💡 Hint

Remember, req.method is the HTTP method used, and req.url is the path requested.

The req.method property holds the HTTP method, here 'GET'. The req.url property holds the path, here '/home'. So the console logs "GET /home".

📝 Syntax

intermediate

Which option correctly accesses the HTTP method and URL in Express?

You want to log the HTTP method and URL of a request in Express. Which code snippet is correct?

A console.log(req.method, req.url);

B console.log(req.Method, req.Url);

C console.log(req.method(), req.url());

D console.log(req['method'], req['url']);

💡 Hint

Check the exact property names and whether they are functions or properties.

In Express, req.method and req.url are properties, not functions, and are lowercase. Option A uses correct casing and syntax.

❓ state_output

advanced

What is the value of req.url after a request to /api/items?sort=asc

If a client sends a GET request to /api/items?sort=asc, what will req.url contain in Express?

A "/api/items?sort=asc"

B "/api/items"

C "sort=asc"

D "/api/items/?sort=asc"

💡 Hint

req.url includes the path and the query string exactly as sent.

req.url contains the full path and query string, so it includes '?sort=asc'.

🔧 Debug

advanced

Why does this code log 'undefined undefined' for req.method and req.url?

Look at this Express middleware:

app.use((request, response) => { console.log(req.method, req.url); response.end('ok'); });

Why does it log 'undefined undefined'?

Express

app.use((request, response) => { console.log(req.method, req.url); response.end('ok'); });

A Because req.method and req.url are not valid properties in Express.

B Because the parameter names are 'request' and 'response', but 'req' is used inside the function.

C Because response.end() must be called before logging.

D Because app.use does not receive req and res parameters.

💡 Hint

Check the variable names used inside the function vs parameters.

The function parameters are named 'request' and 'response', but the code uses 'req' which is undefined, so req.method and req.url are undefined.

🧠 Conceptual

expert

How does Express determine req.url when using a router mounted at a path?

Suppose you mount a router at /api like this:

app.use('/api', router);

Inside the router, what does req.url represent when a request is made to /api/users?

A It contains only the query string part, if any.

B It contains the full original URL, so '/api/users'.

C It is always '/' inside routers.

D It contains the path relative to the mount point, so '/users'.

💡 Hint

Think about how Express routers handle paths relative to where they are mounted.

Inside a router mounted at '/api', req.url is the path relative to '/api', so for '/api/users' it is '/users'.