Add two arrays without using the concat method
<p>Here is a sample of what I would like to do</p>

<pre><code>function test(r){
  var arr = ['d','e','f'];
  r.push(arr);
  /*
  More Code
  */
  return r;
}
var result = test(['a','b','c']);
alert(result.length);//I want this to alert 6
</code></pre>

<p>What I need to do is pass in an array and attach other arrays to the end of it and then return the array.  Because of passing by reference I cannot use <code>array.concat(array2);</code>.  Is there a way to do this without using something like a for loop to add the elements one by one.  I tried something like <code>r.push(arr.join());</code> but that did not work either.  Also, I would like the option of having objects in the arrays so really the <code>r.push(arr.join());</code> doesn't work very well.  </p>
