Hash as named parameters pattern in Ruby - Mini Project: Build & Apply

Hash as Named Parameters Pattern in Ruby

📖 Scenario: You are building a simple greeting system where users can provide their name and optional details like age and city. You want to use a Ruby method that accepts these details as named parameters using a hash.

🎯 Goal: Create a Ruby method that uses a hash as named parameters to greet a user with their name and optionally include their age and city in the greeting.

📋 What You'll Learn

Create a method called greet_user that accepts a single hash parameter named details.

The details hash must have a required key :name.

Optionally, the details hash can have keys :age and :city.

Inside the method, build a greeting string that always includes the :name.

If :age is provided, include it in the greeting.

If :city is provided, include it in the greeting.

Call the method with different hashes to test the greetings.

💡 Why This Matters

🌍 Real World

Using hashes as named parameters is common in Ruby gems and libraries to allow flexible method calls with optional settings.

💼 Career

Understanding this pattern helps you read and write Ruby code that is clean, flexible, and easy to maintain, which is valuable in Ruby development jobs.

1

Create the greet_user method with a details hash parameter

Write a method called greet_user that takes one parameter named details. Inside the method, create a variable greeting and set it to the string "Hello, " plus the value of details[:name].

Ruby

def greet_user(details)
  # Your code here
end

Need a hint?

Use details[:name] to access the name from the hash.

2

Add optional age and city to the greeting inside greet_user

Inside the greet_user method, add code to check if details[:age] exists. If it does, append ", age " plus the age to the greeting string. Then check if details[:city] exists. If it does, append ", from " plus the city to the greeting string.

Ruby

def greet_user(details)
  greeting = "Hello, " + details[:name]
  # Your code here
end

Need a hint?

Use if details[:age] and if details[:city] to check for optional keys.

3

Return the greeting string from the method

Modify the greet_user method to return the greeting string at the end.

Ruby

def greet_user(details)
  greeting = "Hello, " + details[:name]
  greeting += ", age " + details[:age].to_s if details[:age]
  greeting += ", from " + details[:city] if details[:city]
  # Your code here
end

Need a hint?

Use return greeting to send the greeting string back to the caller.

4

Call greet_user with different hashes and print the results

Call greet_user with the hash {name: "Alice"} and print the result. Then call it with {name: "Bob", age: 30} and print the result. Finally, call it with {name: "Carol", city: "Paris"} and print the result.

Ruby

def greet_user(details)
  greeting = "Hello, " + details[:name]
  greeting += ", age " + details[:age].to_s if details[:age]
  greeting += ", from " + details[:city] if details[:city]
  return greeting
end

# Your code here

Need a hint?

Use puts greet_user({name: "Alice"}) to print the greeting.