title: How unperformant are anonymous functions in React component attributes?
body: <p>You're not supposed to use anonymous functions in react attributes, e.g.</p>
  
  <pre><code>&lt;a onClick=()=&gt;doIt('myId')&gt;Aaron&lt;/a&gt;
  </code></pre>
  
  <p>I understand why this creates a performance problem for React's reconciliation because that anonymous function is recreated on every render pass and will thus always trigger a real DOM re-render of some kind.  My question is, for a small component (i.e. not table where every row has a link) is this insignificant?  I mean, React is smart enough just to replace the handler, not to re-render the DOM, right? so the cost is not that high?</p>