title: Making axios call in render does not return anything
body: <p>I am making an axios call in the render of my react native app.</p>
  <pre><code>render() {
      return (
        &lt;View style={{flex: 1, backgroundColor: 'white'}}&gt;
          &lt;ScrollView
            style={styles.scrollView}
            contentContainerStyle={{justifyContent: 'center'}}&gt;
            &lt;Text style={styles.heading}&gt;Checked Out Books&lt;/Text&gt;
            {this.state.books.map((book) =&gt; {
              axios
                .get('http://localhost:3000/books/id/' + book)
                .then((res) =&gt; {
                  console.log(res.data);
                  return (
                    &lt;View&gt;
                      &lt;Image
                        source={{uri: res.data.cover}}
                        height={150}
                        width={110}&gt;&lt;/Image&gt;
                      &lt;Text&gt;{res.data.title}&lt;/Text&gt;
                    &lt;/View&gt;
                  );
                })
                .catch((err) =&gt; {
                  console.log(err);
                  alert('Something went wrong.');
                });
            })}
  </code></pre>
  <p>When the call finishes and it gets to the return step, nothing is returned.</p>
  <p>I don't know why this is happening.
  This segment of code is not returned:</p>
  <pre><code>&lt;View&gt;
    &lt;Image
        source={{uri: res.data.cover}}
        height={150}
        width={110}&gt;&lt;/Image&gt;
        &lt;Text&gt;{res.data.title}&lt;/Text&gt;
  &lt;/View&gt;
  </code></pre>
  <p>Why is this?</p>