title: How to check whether a Storage item is set?
body: <p>How can I check if an item is set in <code>localStorage</code>? Currently I am using</p>
  
  <pre><code>if (!(localStorage.getItem("infiniteScrollEnabled") == true || localStorage.getItem("infiniteScrollEnabled") == false)) {
      // init variable/set default variable for item
      localStorage.setItem("infiniteScrollEnabled", true);
  }
  </code></pre>