title: How do I sum of similar properties in array of objects
body: <p><strong>I asked a similar question earlier today, but the output of this question is different. I asked wrongly the first time :(</strong></p>
  <p>I have a large array, which I have simplified for the question purpose</p>
  <pre><code>[
    {&quot;item1&quot;: 3, &quot;item40&quot;: 2},
    {&quot;item1&quot;: 4, &quot;item40&quot;: 8}
  ]
  </code></pre>
  <p>I would like to end up with this, which is the sum of each similar property in the array of objects. I tried a lot. Doing a forEach whith a forIn inside. But I am stuck. Please help :)</p>
  <p>[7, 10]</p>