Keyword arguments in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of method with keyword arguments

What is the output of this Ruby code?

Ruby

def greet(name:, greeting: "Hello")
  "#{greeting}, #{name}!"
end

puts greet(name: "Alice")

A Hello, Alice!

B Hello, !

C nil

D ArgumentError

💡 Hint

Check the default value of the greeting keyword argument.

The method greet requires a keyword argument 'name' and has a default for 'greeting'. Since only 'name' is passed, 'greeting' uses its default 'Hello'.

❓ Predict Output

intermediate

Keyword argument error

What error does this Ruby code produce?

Ruby

def add(x:, y:)
  x + y
end

add(1, 2)

A TypeError

B ArgumentError

C NoMethodError

D 0

💡 Hint

Check how the method expects arguments to be passed.

The method expects keyword arguments, but positional arguments are given, causing ArgumentError.

🔧 Debug

advanced

Fix the keyword argument usage

This code raises an error. Which option fixes it so it prints "Sum is 7"?

Ruby

def sum_numbers(a:, b:)
  puts "Sum is #{a + b}"
end

sum_numbers(3, 4)

A sum_numbers(a: 3, b: 4)

B sum_numbers(3, b: 4)

C sum_numbers(a = 3, b = 4)

D sum_numbers({a: 3, b: 4})

💡 Hint

Keyword arguments must be passed with their names.

Only option A correctly passes both arguments as keywords matching the method signature.

❓ Predict Output

advanced

Keyword arguments with double splat operator

What is the output of this Ruby code?

Ruby

def details(**info)
  info.keys.sort.join(",")
end

puts details(age: 30, name: "Bob", city: "NY")

A ArgumentError

B name,age,city

C city,name,age

D age,city,name

💡 Hint

The method collects all keyword arguments into a hash and sorts keys alphabetically.

The keys are :age, :name, :city. Sorted alphabetically they are age, city, name.

🧠 Conceptual

expert

Behavior of keyword arguments with defaults and overrides

Given this method:

def configure(timeout: 5, retries: 3)
  "Timeout: #{timeout}, Retries: #{retries}"
end

What is the output of configure(timeout: 10)?

A Timeout: 10, Retries: nil

B Timeout: 5, Retries: 3

C Timeout: 10, Retries: 3

D ArgumentError

💡 Hint

Only the timeout argument is overridden; retries uses default.

The method uses the default retries value 3 because it is not passed in the call.