title: React keys for list of integers
body: <p>I'm trying to render a fixed size array of non unique integers. The list sometimes changed by user interaction. Which keys should I use?
  I tried to use map method with map index as keys but since the array indices are not changed the new values are not rendered.</p>
  
  <pre><code>render() {
      const values = this.props.nonUniqueNumbers.map((number, index) =&gt;
          &lt;div key={index}&gt;{number}&lt;/div&gt;
      );
      return (
          &lt;div&gt;
              { values }
          &lt;/div&gt;
      );
  }
  </code></pre>