Conditional assignment (||=) in Ruby - Mini Project: Build & Apply

Conditional Assignment with ||= in Ruby

📖 Scenario: You are building a simple program to track user preferences for a website. Sometimes users have not set their preferences yet, so you want to assign default values only if the preferences are missing or empty.

🎯 Goal: Learn how to use the conditional assignment operator ||= in Ruby to set default values only when variables are nil or false.

📋 What You'll Learn

Create a variable theme with the value nil

Create a variable font_size with the value nil

Create a variable language with the value "English"

Use ||= to assign "Light" to theme only if it is nil or false

Use ||= to assign 12 to font_size only if it is nil or false

Use ||= to assign "English" to language only if it is nil or false

Print the values of theme, font_size, and language

💡 Why This Matters

🌍 Real World

Websites and apps often need to set default settings for users who haven't chosen their preferences yet.

💼 Career

Understanding conditional assignment helps in writing clean, efficient Ruby code for configuration and data handling.

1

Create initial variables

Create three variables: theme set to nil, font_size set to nil, and language set to "English".

Ruby

# Create variables theme, font_size, and language
# Your code here

Need a hint?

Use = to assign values to variables. nil means no value.

2

Add default values with ||= operator

Use the conditional assignment operator ||= to assign "Light" to theme, 12 to font_size, and "English" to language only if they are nil or false.

Ruby

theme = nil
font_size = nil
language = "English"
# Use ||= to assign default values
# Your code here

Need a hint?

The ||= operator assigns the value only if the variable is nil or false.

3

Check the values after conditional assignment

Write a puts statement to print the values of theme, font_size, and language separated by commas.

Ruby

theme = nil
font_size = nil
language = "English"
theme ||= "Light"
font_size ||= 12
language ||= "English"
# Print the values of theme, font_size, and language
# Your code here

Need a hint?

Use puts with string interpolation to print variables separated by commas.

4

Run and see the output

Run the program and observe the output. It should print Light, 12, English.

Ruby

theme = nil
font_size = nil
language = "English"
theme ||= "Light"
font_size ||= 12
language ||= "English"
puts "#{theme}, #{font_size}, #{language}"  # Run to see output

Need a hint?

If the output is not correct, check your variable names and the use of ||=.