Challenge 1: Implicit Return with Keyword Arguments — Solution

def full_name(first:, last:, middle: nil)
  if middle.nil?
    "#{first} #{last}"
  else
    "#{first} #{middle} #{last}"
  end
end

puts full_name(first: "Philip", last: "Osztromok")
puts full_name(first: "Philip", middle: "James", last: "Osztromok")

=begin
Output:
Philip Osztromok
Philip James Osztromok

Notes:
- first: and last: have no default, so they're required keyword arguments —
  calling full_name without one raises an ArgumentError.
- middle: defaults to nil, making it optional.
- There is no return keyword anywhere in the method. The if/else block is
  itself an expression (Chapter 3), so its result — whichever branch ran —
  becomes the method's implicit return value, since it's the last (and only)
  expression in the method body.
=end