PHP: Aggregating arrays : <p>Assuming I have the following 3 PHP arrays:</p>

<pre><code>$arr1 = [1,2,3,4]
$arr2 = [5,2,4,1]
$arr3 = [2,1,2,2]
</code></pre>

<p>What's the most efficient built-in way that PHP has to add these arrays to elements in the same index of each array. Meaning, the final output would be the following:</p>

<pre><code>$final = [8,5,9,7]
</code></pre>

<p>There should be an easier way than doing <code>final = [$arr1[0]+$arr2[0]+$arr3[0]..]</code> etc. Also, I need to assume there's a variable amount of arrays, so hard coding the math like above isn't correct.</p>
