Type checking with .class and .is_a? in Ruby - Mini Project: Build & Apply

Type checking with .class and .is_a? in Ruby

📖 Scenario: Imagine you are building a simple program that handles different types of items in a store. You want to check the type of each item to decide how to process it.

🎯 Goal: You will create a list of items with different types, set a type to check for, use .class and .is_a? methods to check item types, and print the results.

📋 What You'll Learn

Create an array called items with exact elements: 42, "apple", 3.14, :symbol, and [1, 2, 3]

Create a variable called type_to_check and set it to String

Use a for loop with variable item to iterate over items

Inside the loop, use item.class == type_to_check to check type and store result in class_check

Inside the loop, use item.is_a?(type_to_check) to check type and store result in is_a_check

Print the item, class_check, and is_a_check in each loop iteration

💡 Why This Matters

🌍 Real World

Type checking helps programs decide how to handle different kinds of data, like numbers, text, or lists, which is common in many software applications.

💼 Career

Understanding type checking is important for debugging, writing safe code, and working with object-oriented programming in Ruby and other languages.

1

Create the items array

Create an array called items with these exact elements: 42, "apple", 3.14, :symbol, and [1, 2, 3]

Ruby

# Create the items array with the specified elements
# Your code here

Need a hint?

Use square brackets [] to create an array and separate elements with commas.

2

Set the type_to_check variable

Create a variable called type_to_check and set it to the class String

Ruby

items = [42, "apple", 3.14, :symbol, [1, 2, 3]]
# Set type_to_check to String class
# Your code here

Need a hint?

Assign the class String directly to the variable.

3

Use a for loop to check types

Use a for loop with variable item to iterate over items. Inside the loop, use item.class == type_to_check to check type and store the result in class_check. Also use item.is_a?(type_to_check) to check type and store the result in is_a_check

Ruby

items = [42, "apple", 3.14, :symbol, [1, 2, 3]]
type_to_check = String
# Use a for loop to iterate over items
# Inside the loop, assign class_check and is_a_check
# Your code here

Need a hint?

Use parentheses around item.class == type_to_check to store the boolean result.

4

Print the results inside the loop

Inside the for loop, print the item, class_check, and is_a_check values in each iteration using puts

Ruby

items = [42, "apple", 3.14, :symbol, [1, 2, 3]]
type_to_check = String
for item in items
  class_check = (item.class == type_to_check)
  is_a_check = item.is_a?(type_to_check)
  # Print item, class_check, and is_a_check
  # Your code here
end

Need a hint?

Use string interpolation with #{} inside puts to show values.