title: `each_with_index` not working as I thought
body: <p>I tried to implement the <code>each_with_index</code> method on an array.</p>
  
  <pre><code>def display_weapons
    puts "Your current list of weapons are: "
    @weapons.each_with_index do |weapon, index|
      puts "#{index + 1}. #{weapon}"
    end
  end
  </code></pre>
  
  <p>I call it as:</p>
  
  <pre><code>@weapons = ["Rockets", "Laser", "Photon blaster", "Plasma cannon"]
  puts display_weapons
  </code></pre>
  
  <p>and I get the result:</p>
  
  <pre><code>Your current list of weapons are: 
  1. Rockets
  2. Laser
  3. Photon blaster
  4. Plasma cannon
  Rockets
  Laser
  Photon blaster
  Plasma cannon
  </code></pre>
  
  <p>I'm not getting what I thought I would. I just wanted to ask how this method is working. Why do I get the elements twice? Once with the index+1 and once without.</p>