args.rb

def press(op)
  title = op[:title] || 'no title' 
  body  = op[:body]  || 'none'

  print %Q{
    Title: #{title}
    ----------------
    #{body}
  }
end

# 唯一のHash引数を名前付きの引数のように使う
press title: "Today's topic", body: "It's snow today at Tokyo."


def complex_press(op, ps)
  press(op)
  
  print %Q{
    ps:
     #{ps}
  }
end

# この場合は、{}で囲む必要がある
complex_press(
  {title:  "Today's topic", body: "It's snow today at Tokyo."}, 
  "It's too cold")



def ps_press(ps, op)
  press(op)

   print %Q{
    ps:
     #{ps}
   }
end

# 一番後ろの場合は、{}で囲まなくていい
ps_press("It's too cold",  title:  "Today's topic", body: "It's snow today at Tokyo.")