title: React Performance: Why immutable data could imporve react performance?
body: <p>I just read React official <a href="https://facebook.github.io/react/docs/optimizing-performance.html" rel="nofollow noreferrer">Optimizing Performance</a> guide. One advide of the article is to use immutable data and how to use them.</p>
  
  <p>But it doesn't tell why immutable data could imporve the preformance. And I want to know why.</p>