merge two arrays, merge-sort style
<p>Suppose I have two arrays:</p>

<pre><code>$a1 = array(0,1,2);
$a2 = array(3,4,5);
</code></pre>

<p>I want to be able to do a merge that alternates the arrays and not concatanate them. I want this result:</p>

<pre><code>array(0,3,1,4,2,5);
</code></pre>

<p>Is there a native way to do this as performance is an issue here since I need to do this thousands of times</p>

<p>Please note, I know I can do it like this:</p>

<pre><code>for (var $i = 0; $i &lt; count($a1); $i++) {
    newArray[] = $a1[$i];
    newArray[] = $b1[$i];
}
</code></pre>

<p>I'm looking for a built in way if there is a faster one</p>
