title: Render element using map in React
body: <p>I have a variable called <code>brands</code> which is a list. Under <code>return</code> in <code>render</code>, when I try to map over the list and create new paragraph tag, I get this error: <code>Expected to return a value in arrow function  array-callback-return</code>.</p>
  
  <pre><code>var brands = [];
  
  componentDidMount(){
      database.ref("/brands/").on('child_added', (snapshot)=&gt;{
          var data = snapshot.val();
          console.log(data);
          brands.push(data);
      })
  }
  
  render(){
      return(
          &lt;div&gt;
              {brands.map((brand)=&gt;{
                  &lt;p&gt;{brand}&lt;/p&gt;
              }
              )}
          &lt;/div&gt;
      )
  }
  </code></pre>