A Keyword Init Struct Example (Ruby 2.5+)

pizza_struct.rb

Pizza = Struct.new :crust, :sauce, :toppings, keyword_init: true do
  def to_s
    "#{crust.capitalize} crust with #{sauce} sauce and #{toppings.join ', '}."
  end
end

pizza = Pizza.new sauce: 'tomatoe', toppings: %w[mozarella basil], crust: 'golden brown'
#=> #<struct Pizza crust="golden brown", sauce="tomatoe", toppings=["mozarella", "basil"]>

"Order: #{pizza}"
#=> "Order: Golden brown crust with tomatoe sauce and mozarella, basil."