title: React ajax fetch response undefined
body: <p>I am using the fetch AJAX example from the docs and am fetching this:</p>
  
  <pre><code> https://learnwebcode.github.io/json-example/animals-1.json
  </code></pre>
  
  <p>Here is the componentDidMount part:</p>
  
  <pre><code>componentDidMount() {
  fetch("https://learnwebcode.github.io/json-example/animals-1.json")
    .then(res =&gt; res.json())
    .then(
      (result) =&gt; {
        this.setState({
          isLoaded: true,
          items: result.items
        });
      },
  </code></pre>
  
  <p>I get "uncaught type error in promise, cannot read property map of undefined"</p>
  
  <p>Why is this happening? This is my first attempt to use the fetch API. I have tried to log the response object, but that returns undefined.</p>
  
  <p>The link to the pen is here:</p>
  
  <pre><code> https://codepen.io/damPop/pen/yQLbxV
  </code></pre>