Reject for inverse filtering in Ruby - Mini Project: Build & Apply

Reject for inverse filtering

📖 Scenario: You work in a store that sells fruits. You have a list of fruits with their prices. You want to find all fruits that are not expensive, meaning their price is less than 5.

🎯 Goal: Build a Ruby program that uses reject to filter out expensive fruits from the list, keeping only the affordable ones.

📋 What You'll Learn

Create a hash called fruits with these exact entries: 'apple' => 3, 'banana' => 2, 'cherry' => 7, 'date' => 6, 'elderberry' => 1

Create a variable called price_limit and set it to 5

Use reject on fruits with a block that removes fruits with price greater than or equal to price_limit

Print the resulting hash of affordable fruits

💡 Why This Matters

🌍 Real World

Filtering items based on conditions is common in shopping apps, inventory management, and data analysis.

💼 Career

Knowing how to filter collections efficiently is important for software developers working with data and user interfaces.

1

Create the fruits hash

Create a hash called fruits with these exact entries: 'apple' => 3, 'banana' => 2, 'cherry' => 7, 'date' => 6, 'elderberry' => 1

Ruby

# Create the fruits hash with given entries
# Your code here

Need a hint?

Use curly braces {} to create a hash with keys and values separated by =>.

2

Set the price limit

Create a variable called price_limit and set it to 5

Ruby

fruits = { 'apple' => 3, 'banana' => 2, 'cherry' => 7, 'date' => 6, 'elderberry' => 1 }
# Create price_limit variable and set it to 5
# Your code here

Need a hint?

Just write price_limit = 5 to create the variable.

3

Filter out expensive fruits using reject

Use reject on fruits with a block that removes fruits with price greater than or equal to price_limit. Store the result in a variable called affordable_fruits

Ruby

fruits = { 'apple' => 3, 'banana' => 2, 'cherry' => 7, 'date' => 6, 'elderberry' => 1 }
price_limit = 5
# Use reject to remove fruits with price >= price_limit
# Your code here

Need a hint?

Use reject { |fruit, price| price >= price_limit } to remove expensive fruits.

4

Print the affordable fruits

Write puts affordable_fruits to print the resulting hash of affordable fruits

Ruby

fruits = { 'apple' => 3, 'banana' => 2, 'cherry' => 7, 'date' => 6, 'elderberry' => 1 }
price_limit = 5
affordable_fruits = fruits.reject { |fruit, price| price >= price_limit }
# Print affordable_fruits
# Your code here

Need a hint?

Use puts affordable_fruits to show the filtered fruits.