Offset-based pagination in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this offset-based pagination calculation?

Given a REST API that uses offset-based pagination, the client requests page 3 with a page size of 10. What is the offset value sent to the server?

Rest API

page = 3
page_size = 10
offset = (page - 1) * page_size
print(offset)

A 20

B 30

C 3

D 10

💡 Hint

Offset is how many items to skip before starting to collect the page.

Offset is calculated as (page - 1) * page_size. For page 3 and page size 10, offset = (3 - 1) * 10 = 20.

🧠 Conceptual

intermediate

Which statement best describes offset-based pagination?

Choose the statement that correctly describes offset-based pagination in REST APIs.

A It only works with APIs that return data sorted by timestamp.

B It uses a page number and page size to calculate how many items to skip before fetching data.

C It fetches all data at once and then slices it on the client side.

D It uses a cursor to mark the last item fetched and fetches the next set after it.

💡 Hint

Think about how offset is calculated using page number and size.

Offset-based pagination calculates the number of items to skip using page number and page size, then fetches the next set of items.

🔧 Debug

advanced

Why does this offset-based pagination code return an empty list on page 1?

Look at the code below. It is supposed to return the first page of results but returns an empty list. What is the cause?

Rest API

def get_page(data, page, page_size):
    offset = page * page_size
    return data[offset:offset + page_size]

items = list(range(5))
print(get_page(items, 1, 10))

A The slice syntax is incorrect; it should be data[offset:page_size].

B The data list is empty, so it always returns an empty list.

C The offset calculation should subtract 1 from page before multiplying by page_size.

D The page_size should be added to offset twice.

💡 Hint

Remember that page 1 means no items skipped.

Offset should be (page - 1) * page_size. The current code skips the first page entirely by starting at offset = page * page_size.

📝 Syntax

advanced

Which option correctly implements offset-based pagination in Python?

Choose the code snippet that correctly calculates offset and slices the data list for pagination.

Rest API

data = list(range(100))
page = 4
page_size = 15

A

offset = (page - 1) * page_size
page_data = data[offset:offset + page_size]

B

offset = page * page_size
page_data = data[offset:offset + page_size]

C

offset = (page + 1) * page_size
page_data = data[offset:offset + page_size]

D

offset = page_size - page
page_data = data[offset:offset + page_size]

💡 Hint

Offset must skip items from previous pages.

Offset is (page - 1) * page_size to skip items from earlier pages. Then slice from offset to offset + page_size.

🚀 Application

expert

How many items will be returned by this offset-based pagination request?

Assume a dataset of 95 items. A client requests page 10 with a page size of 10 using offset-based pagination. How many items will the server return?

A 0

B 10

C 15

D 5

💡 Hint

Calculate offset and see how many items remain after skipping.

Offset = (10 - 1) * 10 = 90. There are 95 items total, so 95 - 90 = 5 items remain to return.