Find/detect for first match in Ruby - Mini Project: Build & Apply

Find the First Even Number in a List

📖 Scenario: Imagine you have a list of numbers from a game score sheet. You want to find the first even number to see when the player first scored an even point.

🎯 Goal: You will write a Ruby program that finds the first even number in a list using the find method.

📋 What You'll Learn

Create an array called scores with the exact numbers: 3, 7, 8, 10, 15

Create a variable called is_even that holds a lambda to check if a number is even

Use the find method with is_even to get the first even number from scores

Print the found even number using puts

💡 Why This Matters

🌍 Real World

Finding the first item that meets a condition is common in data filtering, like finding the first available appointment or the first product in stock.

💼 Career

Many programming jobs require filtering lists or arrays to find specific data quickly, making this skill very useful.

1

Create the list of scores

Create an array called scores with these exact numbers: 3, 7, 8, 10, 15

Ruby

# Create the array scores with the numbers 3, 7, 8, 10, 15
# Your code here

Need a hint?

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

2

Create a lambda to check even numbers

Create a variable called is_even that holds a lambda which returns true if a number is even

Ruby

scores = [3, 7, 8, 10, 15]
# Create a lambda called is_even to check if a number is even
# Your code here

Need a hint?

Use ->(num) { num.even? } to create a lambda that checks if num is even.

3

Find the first even number

Use the find method on scores with the is_even lambda to get the first even number and store it in first_even

Ruby

scores = [3, 7, 8, 10, 15]
is_even = ->(num) { num.even? }
# Use find with is_even to get the first even number and store in first_even
# Your code here

Need a hint?

Use scores.find(&is_even) to find the first number where is_even returns true.

4

Print the first even number

Print the variable first_even using puts to show the first even number found

Ruby

scores = [3, 7, 8, 10, 15]
is_even = ->(num) { num.even? }
first_even = scores.find(&is_even)
# Print the first_even variable
# Your code here

Need a hint?

Use puts first_even to print the value.