title: How to calculate sum of object keys in array - javascript
body: <h1>Question</h1>
  
  <p>I am working with firebase and react native.</p>
  
  <p>I have returned an array from my firebase database that looks like this.</p>
  
  <pre><code>[Object, Object, Object]
  </code></pre>
  
  <p>Under each object I have returned a single item, "level:4".</p>
  
  <p>So I have three objects containing 4,5,6. How do I sum these together?</p>
  
  <p>Thanks!</p>