title: How to extract property of array in nested array
body: <p>I have an array, which contains array of objects. I need to extract the property value "id" of items that have objects.</p>
  
  <p>Example of array:</p>
  
  <pre><code>let myArray = [
      [ {id: "1"}, {id: "2"} ],
      [],
      [],
      [ {id: "3"} ]
  ]
  </code></pre>
  
  <p>How can I extract and create an array like this:</p>
  
  <pre><code>["1", "2", "3"]
  </code></pre>
  
  <p>I tried this:</p>
  
  <pre><code>tagIds = myArray.map(id =&gt;{id})
  </code></pre>