title: How to remove outer array from a nested array?
body: <p>If I have the following <code>arr = [13,12,31,31]</code> Now say I want to push in another set of numbers like <code>12,13,54,32</code></p>
  
  <p>So I can do <code>arr &lt;&lt; [12,13,54,32]</code> but now I have <code>[13,12,31,31,[12,13,54,32]]</code> </p>
  
  <p>So how can I remove the outside array? <code>arr = arr.pop</code> <em>works sometimes</em> but I'm guessing that a better way exists. Please enlighten. </p>