title: React map item shows nothing
body: <pre><code>import React from 'react';
  import &quot;./css/App.css&quot;
  
  
  const App= () =&gt;{
    const test=[&quot;1&quot;,&quot;2&quot;];
    return
      test.map((item)=&gt;{
        return
          &lt;div key={item} &gt;{item}&lt;/div&gt;
      })
  }
  
  export default App;
  </code></pre>
  <p>This is so weird. I checked the console and it doesn't say anything. Please kindly advise me what mistake I 've made or what possibilities would cause this. Thanks.</p>