Finding the difference between arrays and update
<p>I am wondering, what is the most efficient way to compare two arrays in a way that:</p>

<ol>
<li>it finds the missing objects from array A compared to array B, and adds them to object A;</li>
<li>if object from A is different from object B, it updates the properties (objects identified by property 'id')</li>
</ol>

<p>Any ideas?</p>