title: Using "Boolean" as the argument to .filter() in JavaScript
body: <p>Recently I've learned that you can use the <code>Boolean</code> keyword to check whether a boolean value is <code>false</code>, e.g. this, where the  <code>arrayOfSheeps</code> is simply an array of boolean values.</p>
  <pre class="lang-js prettyprint-override"><code>function countSheeps(arrayOfSheeps) {
    return arrayOfSheeps.filter(Boolean).length;
  }
  </code></pre>
  <p>As I've been unable to find anything about using 'Boolean' as a keyword, I was wondering if there are any other uses for the word, or even just any resources I can use to learn about it.</p>