title: JQuery .toggle() Not understood
body: <p>I am newbie to the programming and currently learning through udemy. Having trouble understanding the <code>toggle()</code> method logic. I would highly appreciate if anyone could help me understand the following <code>toggle</code> method functionality.</p>
  <p>I am confused at <code>var started  = false</code> I hope it means start only if it is false.</p>
  <pre><code> var started = false;
   var level = 0;
  
   $(document).on(&quot;keydown&quot;, function(){
    if (!started) {
    $(&quot;#level-title&quot;).text(&quot;Level&quot; + level);
    nextSequence();
    started = true;
   }
  })
  </code></pre>