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

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this page-based pagination response?

Given a REST API endpoint that returns paginated results with the following JSON response for page 2 with page size 3:

{
  "page": 2,
  "page_size": 3,
  "total_items": 8,
  "items": ["item4", "item5", "item6"]
}

What will be the value of items in the response for page 3?

A ["item6", "item7", "item8"]

B ["item7", "item8", "item9"]

C ["item7", "item8"]

D []

💡 Hint

Think about how many items are left after page 2 and the page size.

Page size is 3, total items are 8. Page 1 has items 1-3, page 2 has items 4-6, so page 3 has items 7 and 8 only.

🧠 Conceptual

intermediate

Which parameter is essential for page-based pagination?

In page-based pagination, which parameter is necessary to specify which set of results to retrieve?

A cursor

B page

C limit

D offset

💡 Hint

Page-based pagination uses page numbers to navigate.

The page parameter tells the API which page of results to return.

❓ Predict Output

advanced

What is the output of this pagination calculation?

Consider this Python function that calculates the total number of pages:

def total_pages(total_items, page_size):
    return (total_items + page_size - 1) // page_size

print(total_pages(25, 10))

What is the output?

Rest API

def total_pages(total_items, page_size):
    return (total_items + page_size - 1) // page_size

print(total_pages(25, 10))

A 4

B 2

C Error

D 3

💡 Hint

Think about how integer division rounds down and how the formula accounts for leftover items.

The formula rounds up the division to count partial pages. 25 items with page size 10 means 3 pages.

🔧 Debug

advanced

Why does this pagination code return an empty list for page 1?

Given this Python code snippet for page-based pagination:

def get_page(items, page, page_size):
    start = page * page_size
    end = start + page_size
    return items[start:end]

items = [1,2,3,4,5]
print(get_page(items, 1, 2))

Why does it return [3,4] instead of the expected [1,2] for page 1?

Rest API

def get_page(items, page, page_size):
    start = page * page_size
    end = start + page_size
    return items[start:end]

items = [1,2,3,4,5]
print(get_page(items, 1, 2))

A Because the start index calculation should be (page - 1) * page_size

B Because the items list is empty

C Because the end index is calculated incorrectly and should be page * page_size

D Because page indexing starts at 0, so page 1 is actually the second page

💡 Hint

Think about whether page numbers start at 0 or 1.

The function treats page 1 as the second page because it multiplies page by page_size directly. To get the first page, it should subtract 1 from page.

🚀 Application

expert

How many pages will be returned for 103 items with page size 20?

You have a dataset with 103 items. You want to paginate them with a page size of 20 items per page.

How many pages will the API return?

A 6

B 5

C 7

D 8

💡 Hint

Divide total items by page size and round up.

103 divided by 20 is 5.15, so you need 6 pages to cover all items.