Why blocks are fundamental to Ruby - See It in Action

Why blocks are fundamental to Ruby

📖 Scenario: Imagine you are organizing a small event and you want to send personalized messages to each guest. You want to use a simple way to apply a custom action to each guest's name.

🎯 Goal: You will create a list of guest names, set up a block to customize messages, and then use the block to print personalized greetings for each guest. This will show how blocks let you pass custom code to methods in Ruby.

📋 What You'll Learn

Create an array called guests with the exact names: 'Alice', 'Bob', 'Charlie'

Create a variable called message_block that holds a block which takes one parameter name and returns the string "Hello, #{name}! Welcome to the event."

Use the map method on guests with the message_block to generate personalized greetings for each guest

Print each greeting exactly as returned by the block

💡 Why This Matters

🌍 Real World

Blocks let you write flexible code that can do different things with the same method, like sending custom messages to guests or processing lists of data.

💼 Career

Understanding blocks is essential for Ruby developers because many Ruby libraries and frameworks use blocks to let you customize behavior easily.

1

Create the guest list

Create an array called guests with these exact names: 'Alice', 'Bob', and 'Charlie'.

Ruby

# Create the guests array with 'Alice', 'Bob', and 'Charlie'
guests = []
# Your code here

Need a hint?

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

2

Create a block for personalized messages

Create a variable called message_block that holds a block. The block should take one parameter called name and return the string "Hello, #{name}! Welcome to the event." using string interpolation.

Ruby

guests = ['Alice', 'Bob', 'Charlie']
# Create message_block that takes name and returns greeting
message_block = nil
# Your code here

Need a hint?

Use Proc.new { |name| ... } to create a block and return the greeting string.

3

Use the block with each guest

Use the map method on the guests array with the message_block to get a greeting for each guest. Store the greetings in a new array called greetings.

Ruby

guests = ['Alice', 'Bob', 'Charlie']
message_block = Proc.new { |name| "Hello, #{name}! Welcome to the event." }
# Use map with message_block to create greetings array
greetings = []
# Your code here

Need a hint?

Use map with &message_block to apply the block to each guest and collect results.

4

Print the personalized greetings

Use a for loop to print each greeting from the greetings array exactly as it is.

Ruby

guests = ['Alice', 'Bob', 'Charlie']
message_block = Proc.new { |name| "Hello, #{name}! Welcome to the event." }
greetings = guests.map(&message_block)
# Print each greeting
# Your code here

Need a hint?

Use for greeting in greetings and puts greeting to print each message.