Nested lists in R Programming - Mini Project: Build & Apply

Working with Nested Lists in R

📖 Scenario: Imagine you are organizing a small library. Each shelf holds a list of books, and each book has a title and an author. You want to store this information in a nested list in R.

🎯 Goal: Create a nested list in R where each shelf is a list of books, and each book is represented by a list containing its title and author. Then, extract and print the title of the first book on the second shelf.

📋 What You'll Learn

Create a nested list called library with two shelves.

Each shelf should be a list of two books.

Each book should be a list with elements title and author.

Create a variable called first_book_second_shelf to store the title of the first book on the second shelf.

Print the value of first_book_second_shelf.

💡 Why This Matters

🌍 Real World

Nested lists help organize complex data like library catalogs, menus, or survey responses.

💼 Career

Understanding nested data structures is important for data analysis, software development, and managing hierarchical information.

1

Create the nested list library

Create a nested list called library with two shelves. Each shelf should be a list of two books. Each book should be a list with elements title and author. Use these exact values:

First shelf:
- Book 1: title = "The Hobbit", author = "J.R.R. Tolkien"
- Book 2: title = "1984", author = "George Orwell"

Second shelf:
- Book 1: title = "Pride and Prejudice", author = "Jane Austen"
- Book 2: title = "To Kill a Mockingbird", author = "Harper Lee"

R Programming

# Create the nested list 'library' with the two shelves and books
# Your code here

Need a hint?

Use list() to create lists inside lists. Each shelf is a list of two book lists.

2

Create variable first_book_second_shelf

Create a variable called first_book_second_shelf and assign it the title of the first book on the second shelf from the library nested list.

R Programming

library <- list(
  shelf1 = list(
    list(title = "The Hobbit", author = "J.R.R. Tolkien"),
    list(title = "1984", author = "George Orwell")
  ),
  shelf2 = list(
    list(title = "Pride and Prejudice", author = "Jane Austen"),
    list(title = "To Kill a Mockingbird", author = "Harper Lee")
  )
)
# Assign the title of the first book on the second shelf to 'first_book_second_shelf'
# Your code here

Need a hint?

Use $ and double square brackets [[ ]] to access nested list elements.

3

Print the title stored in first_book_second_shelf

Write a print() statement to display the value of the variable first_book_second_shelf.

R Programming

library <- list(
  shelf1 = list(
    list(title = "The Hobbit", author = "J.R.R. Tolkien"),
    list(title = "1984", author = "George Orwell")
  ),
  shelf2 = list(
    list(title = "Pride and Prejudice", author = "Jane Austen"),
    list(title = "To Kill a Mockingbird", author = "Harper Lee")
  )
)
first_book_second_shelf <- library$shelf2[[1]]$title
# Print the title of the first book on the second shelf
# Your code here

Need a hint?

Use print() to show the value stored in a variable.

4

Final Output Check

Run the program to print the title of the first book on the second shelf.

R Programming

library <- list(
  shelf1 = list(
    list(title = "The Hobbit", author = "J.R.R. Tolkien"),
    list(title = "1984", author = "George Orwell")
  ),
  shelf2 = list(
    list(title = "Pride and Prejudice", author = "Jane Austen"),
    list(title = "To Kill a Mockingbird", author = "Harper Lee")
  )
)
first_book_second_shelf <- library$shelf2[[1]]$title
print(first_book_second_shelf)
# Run the program to see the output

Need a hint?

The output should be the title of the first book on the second shelf.