Sort_by for custom sorting in Ruby - Mini Project: Build & Apply

Sort_by for custom sorting

📖 Scenario: You work in a bookstore. You have a list of books with their titles and number of pages. You want to sort the books by their page count to help customers find shorter or longer books easily.

🎯 Goal: Build a Ruby program that sorts a list of books by their page count using sort_by.

📋 What You'll Learn

Create an array of hashes called books with exact entries for title and pages

Create a variable called max_pages with the value 300

Use sort_by on books to sort by the number of pages

Print the sorted list of book titles and their page counts

💡 Why This Matters

🌍 Real World

Sorting lists of items by a property is common in apps like bookstores, libraries, or online shops to help users find what they want quickly.

💼 Career

Knowing how to use sort_by for custom sorting is a basic but important skill for Ruby developers working with collections of data.

1

Create the books array

Create an array called books with these exact hashes: { title: 'Ruby Basics', pages: 150 }, { title: 'Advanced Ruby', pages: 320 }, { title: 'Rails Guide', pages: 280 }, { title: 'JavaScript Essentials', pages: 200 }

Ruby

# Create the books array with hashes for title and pages
# Your code here

Need a hint?

Remember to create an array with hashes inside, each hash having keys :title and :pages.

2

Add max_pages variable

Create a variable called max_pages and set it to 300

Ruby

books = [
  { title: 'Ruby Basics', pages: 150 },
  { title: 'Advanced Ruby', pages: 320 },
  { title: 'Rails Guide', pages: 280 },
  { title: 'JavaScript Essentials', pages: 200 }
]
# Create max_pages variable and set it to 300
# Your code here

Need a hint?

Just create a variable named max_pages and assign 300 to it.

3

Sort books by pages using sort_by

Use sort_by on books to create a new array called sorted_books sorted by the :pages key

Ruby

books = [
  { title: 'Ruby Basics', pages: 150 },
  { title: 'Advanced Ruby', pages: 320 },
  { title: 'Rails Guide', pages: 280 },
  { title: 'JavaScript Essentials', pages: 200 }
]
max_pages = 300
# Use sort_by to sort books by pages into sorted_books
# Your code here

Need a hint?

Use sort_by with a block that returns book[:pages].

4

Print the sorted books

Use a for loop with variable book to iterate over sorted_books and print each book's title and pages in the format: "Title: Ruby Basics, Pages: 150"

Ruby

books = [
  { title: 'Ruby Basics', pages: 150 },
  { title: 'Advanced Ruby', pages: 320 },
  { title: 'Rails Guide', pages: 280 },
  { title: 'JavaScript Essentials', pages: 200 }
]
max_pages = 300
sorted_books = books.sort_by { |book| book[:pages] }
# Print each book's title and pages from sorted_books
# Your code here

Need a hint?

Use a for loop and puts with string interpolation to print each book's details.