React performance implications of long key value on component : <p>How does length of a string applied to some component collection created from some set of data like this:</p>

<pre><code>{this.state.list.map(item =&gt; {
  const url = item.url;
  return (
    &lt;ListItemComponent url={url} key={url}/&gt;
  );
})}
</code></pre>

<p><strong>Are there some restrictions? What are performance implications of having long key values?</strong></p>

<p><em>Background. Sometimes we need to create list of items that are very long (like urls with lots of parameters encoded) and only suitable/unique thing to use as natural key is this very long thing.</em></p>
