strings

# Strings, and `to_s`: how a type says what it looks like.

s = "Hello, iyi"
puts s.size
puts s.upcase
puts s.downcase
puts s.includes?("iyi")
puts s + "!"
puts s.split(' ')

# Interpolation calls `to_s` on whatever is inside `#{}`.
puts "#{1 + 1} and #{true} and #{[1, 2]}"

# Give your own type a `to_s`, and it prints the way you say.
struct Money
  def initialize(@lira : Int32, @kurus : Int32)
  end

  def to_s : String
    "#{@lira},#{@kurus.to_s.rjust(2, '0')} TL"
  end
end

price = Money.new(12, 5)
puts price.to_s
puts "total: #{price}"

# Padding lines up columns.
puts "item".ljust(8) + "12"
puts "total".ljust(8) + "99"