title: Iterating through each letter of a string
body: <p>I am trying to iterate through each letter of a string to print out a word.</p>
  
  <pre><code>greeting = "hello"
  extract = 0
  letter = greeting[extract]
  
  while extract &lt; greeting.length
    p letter
    extract += 1
  end
  </code></pre>
  
  <p>The result is <code>"h", "h", "h" ,"h", "h"</code> instead of hello. What am I doing wrong?</p>