Dig method for nested access in Ruby - Mini Project: Build & Apply

Dig method for nested access

📖 Scenario: Imagine you have information about a library's book collection stored in nested hashes. You want to find details about specific books easily without checking each level manually.

🎯 Goal: You will create a nested hash representing books, set up keys to access, use the dig method to get nested values safely, and print the result.

📋 What You'll Learn

Create a nested hash called library with specific book details

Create an array called keys with the path to a nested value

Use the dig method on library with *keys to get the nested value

Print the result using puts

💡 Why This Matters

🌍 Real World

Nested data structures like hashes inside hashes are common in real applications such as configuration files, JSON data, or API responses. The <code>dig</code> method helps access deep values without errors.

💼 Career

Understanding how to safely access nested data is important for backend developers, data engineers, and anyone working with complex data formats.

1

Create the nested hash library

Create a nested hash called library with this exact structure: { 'fiction' => { '1984' => { 'author' => 'George Orwell', 'year' => 1949 } } }

Ruby

# Create the nested hash called library
# Your code here

Need a hint?

Use curly braces {} to create hashes inside hashes.

2

Create the array keys for nested access

Create an array called keys with these exact strings: 'fiction', '1984', 'author'

Ruby

library = { 'fiction' => { '1984' => { 'author' => 'George Orwell', 'year' => 1949 } } }
# Create the array keys with 'fiction', '1984', 'author'
# Your code here

Need a hint?

Use square brackets [] to create an array with strings.

3

Use dig to get the nested author

Use the dig method on library with *keys to get the nested author name and store it in a variable called author_name

Ruby

library = { 'fiction' => { '1984' => { 'author' => 'George Orwell', 'year' => 1949 } } }
keys = ['fiction', '1984', 'author']
# Use dig with *keys on library and assign to author_name
# Your code here

Need a hint?

Use dig with the splat operator * to pass array elements as arguments.

4

Print the author name

Print the variable author_name using puts to display the author's name

Ruby

library = { 'fiction' => { '1984' => { 'author' => 'George Orwell', 'year' => 1949 } } }
keys = ['fiction', '1984', 'author']
author_name = library.dig(*keys)
# Print author_name
# Your code here

Need a hint?

Use puts author_name to print the value.