title: Undefined Method Error - Modifying a Hash in a Case Statement After
body: <p>So, I made a hash called "facing". I call a case statement after, where I want to subtract 1 from the value if the user types L, or (I didn't get here yet) add 1 if the input = 'R'.</p>
  
  <pre><code>class Rover
    attr_accessor :orientation
  end
  
  #facing = Hash.new
  
  facing = {
    0 =&gt; 0
  }
  
  bot = Rover.new
  bot.orientation = "N"
  
  puts "Bot's current orientation is: " + bot.orientation 
  puts "What direction to turn ('L' or 'R')?"
  
  input = gets.chomp.to_s.capitalize
  
  case input
    when input = 'L'
      facing do |key, value|
        value - 1
      end
  end
  </code></pre>
  
  <p>The problem is that I get a method undefined (facing) error message. What am I doing wrong?</p>