title: How to use this.id in function
body: <p>Instead of assigning variable for this.id, does anyone know the syntax of how would I pass this.id into findIndex function?</p>
  
  <pre><code>listing.slideUp(500, function() {
      var listing_id = this.id;
      // I'd like it to say car[0].id == this.id ?
      var index = cars.findIndex(function(car) { return car[0].id === listing_id });
      if (index &gt; -1) {
          cars.splice(index, 1);
      }
  });
  </code></pre>