Frozen objects in Ruby - Mini Project: Build & Apply

Frozen objects

📖 Scenario: Imagine you are managing a list of favorite fruits in a program. Sometimes, you want to make sure this list does not change accidentally after you set it.

🎯 Goal: You will create a list of fruits, freeze it to prevent changes, and then try to modify it to see what happens.

📋 What You'll Learn

Create an array called fruits with the exact values: 'apple', 'banana', 'cherry'

Create a variable called frozen_fruits that is the frozen version of fruits

Attempt to add 'orange' to frozen_fruits using push

Print frozen_fruits to show the result

💡 Why This Matters

🌍 Real World

Freezing objects is useful when you want to keep data safe and unchanged, like configuration settings or fixed lists.

💼 Career

Understanding frozen objects helps you write safer Ruby code, which is important for roles like Ruby developer or backend engineer.

1

Create the fruits array

Create an array called fruits with these exact strings: 'apple', 'banana', 'cherry'

Ruby

# Create the fruits array
# Your code here

Need a hint?

Use square brackets [] to create an array with the given strings separated by commas.

2

Freeze the fruits array

Create a variable called frozen_fruits and set it to the frozen version of the fruits array using the freeze method

Ruby

fruits = ['apple', 'banana', 'cherry']
# Freeze the fruits array
# Your code here

Need a hint?

Call freeze on fruits and assign it to frozen_fruits.

3

Try to modify the frozen array

Use the push method to add the string 'orange' to the frozen_fruits array

Ruby

fruits = ['apple', 'banana', 'cherry']
frozen_fruits = fruits.freeze
# Try to add 'orange' to frozen_fruits
# Your code here

Need a hint?

Call push('orange') on frozen_fruits to try adding an item.

4

Print the frozen array

Write a puts statement to print the frozen_fruits array

Ruby

fruits = ['apple', 'banana', 'cherry']
frozen_fruits = fruits.freeze
frozen_fruits.push('orange')
# Print frozen_fruits
# Your code here

Need a hint?

Use puts frozen_fruits to print each fruit on its own line.

Note: Since the array is frozen, adding 'orange' will cause an error and the program will stop before printing.