title: Find all values by specific key in a deep nested object
body: <p>How would I find all values by specific key in a deep nested object?</p>
  <p>For example, if I have an object like this:</p>
  <pre><code>const myObj = {
    id: 1,
    children: [
      {
        id: 2,
        children: [
          {
            id: 3
          }
        ]
      },
      {
        id: 4,
        children: [
          {
            id: 5,
            children: [
              {
                id: 6,
                children: [
                  {
                    id: 7,
                  }
                ]
              }
            ]
          }
        ]
      },
    ]
  }
  </code></pre>
  <p>How would I get an array of all values throughout all nests of this obj by the key of <code>id</code>.</p>
  <p>Note: <code>children</code> is a consistent name, and <code>id</code>'s won't exist outside of a <code>children</code> object.</p>
  <p>So from the obj, I would like to produce an array like this:</p>
  <pre><code>const idArray = [1, 2, 3, 4, 5, 6, 7]
  </code></pre>