Pagination patterns in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the default page number to 1 if not provided.

Node.js

const page = parseInt(req.query.page) || [1];

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

A1

B0

Cnull

Dundefined

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as the default page number, which may cause confusion.

Using null or undefined which do not default properly.

The default page number should be 1 to start pagination from the first page.

2fill in blank

medium

Complete the code to calculate the number of items to skip based on page and limit.

Node.js

const skip = (page - 1) * [1];

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

Apage

Bcount

Climit

Doffset

Attempts:

3 left

💡 Hint

Common Mistakes

Using page instead of limit causes wrong skip calculation.

Using offset or count which are not defined here.

We multiply (page - 1) by the limit to skip the correct number of items.

3fill in blank

hard

Fix the error in the MongoDB query to apply pagination correctly.

Node.js

const results = await collection.find().skip([1]).limit(limit).toArray();

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

A(page - 1) * limit

Bskip

Cpage

Doffset

Attempts:

3 left

💡 Hint

Common Mistakes

Passing page directly to skip causes wrong results.

Using undefined variables like offset.

The skip value must be calculated as (page - 1) * limit to get the correct starting point.

4fill in blank

hard

Fill both blanks to create a paginated API response with total pages and current page.

Node.js

const totalPages = Math.ceil(totalItems / [1]);
const response = { currentPage: [2], totalPages };

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

Alimit

Bpage

Cskip

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using skip instead of limit for total pages calculation.

Mixing up page and skip values.

Total pages is total items divided by limit, rounded up. Current page is the page number requested.

5fill in blank

hard

Fill all three blanks to implement cursor-based pagination with limit and cursor parameters.

Node.js

const query = {};
if ([1]) {
  query._id = { $gt: [2] };
}
const results = await collection.find(query).limit([3]).toArray();

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

Acursor

Climit

Dpage

Attempts:

3 left

💡 Hint

Common Mistakes

Using page instead of cursor for _id comparison.

Not limiting the results properly.

If a cursor is provided, query for items with _id greater than cursor. Limit the results by the limit value.