title: How do i flip a 2d array from top to bottom?
body: <p>I'm trying to flip a 2d array from top to bottom. </p>
  
  <p>E.G.   1,2,3</p>
  
  <pre><code>    4,5,6
  
      7,8,9
  
      into
  
      7,8,9
  
      4,5,6
  
      1,2,3
  </code></pre>