title: Is there a “not in” operator in JavaScript for checking object properties?
body: <p>Is there any sort of "not in" operator in JavaScript to check if a property does not exist in an object? I couldn’t find anything about this around Google or Stack Overflow. Here’s a small snippet of code I’m working on where I need this kind of functionality:</p>
  
  <pre><code>var tutorTimes = {};
  
  $(checked).each(function(idx){
    id = $(this).attr('class');
  
    if(id in tutorTimes){}
    else{
      //Rest of my logic will go here
    }
  });
  </code></pre>
  
  <p>As you can see, I’d be putting everything into the <code>else</code> statement. It seems wrong to me to set up an <code>if</code>–<code>else</code> statement just to use the <code>else</code> portion.</p>