Validating route params and query in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the route parameter 'id' in Express.

Express

app.get('/user/:id', (req, res) => {
  const userId = req.params.[1];
  res.send(`User ID is ${userId}`);
});

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

Abody

Bquery

Cid

Dparam

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.query instead of req.params for route parameters.

Trying to access req.param instead of req.params.

Route parameters in Express are accessed via req.params using the parameter name, here 'id'.

2fill in blank

medium

Complete the code to access the query parameter 'search' in Express.

Express

app.get('/items', (req, res) => {
  const searchTerm = req.[1].search;
  res.send(`Search term is ${searchTerm}`);
});

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

Aquery

Bparams

Cbody

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.params instead of req.query for query parameters.

Trying to access query parameters from req.body.

Query parameters are accessed via req.query in Express.

3fill in blank

hard

Fix the error in validating that the 'id' route parameter is a number.

Express

app.get('/product/:id', (req, res) => {
  const id = req.params.[1];
  if (isNaN(id)) {
    return res.status(400).send('Invalid ID');
  }
  res.send(`Product ID is ${id}`);
});

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

Aparams

BproductId

Cquery

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong parameter name that does not exist in the route.

Trying to get the parameter from req.query instead of req.params.

The route parameter name is 'id', so use req.params.id to get it.

4fill in blank

hard

Fill both blanks to validate that the 'page' query parameter is a positive integer.

Express

app.get('/list', (req, res) => {
  const page = parseInt(req.[1].[2], 10);
  if (isNaN(page) || page < 1) {
    return res.status(400).send('Invalid page number');
  }
  res.send(`Page number is ${page}`);
});

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

Aquery

Bparams

Cpage

Dbody

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.params instead of req.query for query parameters.

Using a wrong parameter name.

Query parameters are in req.query, and the parameter name is 'page'.

5fill in blank

hard

Fill all three blanks to validate that the 'userId' route param is numeric and 'sort' query param is either 'asc' or 'desc'.

Express

app.get('/users/:userId', (req, res) => {
  const userId = req.params.[1];
  const sort = req.query.[2];
  if (isNaN(userId)) {
    return res.status(400).send('Invalid user ID');
  }
  if (sort !== 'asc' && sort !== [3]) {
    return res.status(400).send('Invalid sort order');
  }
  res.send(`User ID: ${userId}, Sort: ${sort}`);
});

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

AuserId

Bsort

C'desc'

D'asc'

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up route params and query params.

Not checking both allowed sort values.

Using quotes incorrectly around string values.

Use req.params.userId for the route param, req.query.sort for the query param, and check if sort equals 'asc' or 'desc'.