title: Array.prototype.includes vs. Array.prototype.indexOf
body: <p>Beyond the improved readability, is there any advantage to <code>includes</code> over <code>indexOf</code>?  They seem identical to me.</p>
  
  <p>What is the difference between this</p>
  
  <pre><code>var x = [1,2,3].indexOf(1) &gt; -1; //true
  </code></pre>
  
  <p>And this?    </p>
  
  <pre><code>var y = [1,2,3].includes(1); //true
  </code></pre>