title: Javascript: push an entire list?
body: <p>Is there a built in way to append one list into another like so:</p>
  
  <pre><code>var a = [1,2,3];
  a.append([4,5]);
  // now a is [1,2,3,4,5];
  </code></pre>
  
  <p><code>concat()</code> does something similar but returns the result. I want something that modifies the existing list like <code>push()</code></p>