What is the most efficient way of merging [1,2] and [7,8] into [[1,7], [2,8]]
<p>Given 2 arrays [1,2] and [7,8] what is the most efficient way of merging that to form [[1,7], [2,8]]. I know we can do this:</p>

<pre><code>a1 = [1,2], a2 = [7,8], a3=[];
for (var i=0; i&lt;a1.length; i++) {
  a3.push([a1[i], a2[i]]);
}
</code></pre>

<p>I am dealing with a large array. So I want to see if there is a better way.</p>
