title: Affix is not a function
body: <p>I've been trying to create a sticky sidebar for a while on my Wordpress site with Bootstrap 4 Alpha. I've found other issues similar to this one online and most suggest putting the code inside of</p>
  
  <pre><code>jQuery(document).ready(function($){
  });
  </code></pre>
  
  <p>I've tried this but was not successful. I've also tried rearranging the order of how my scripts are being called and that hasn't worked either.</p>
  
  <p>Here is the basic Bootstrap sidebar code that I currently have</p>
  
  <pre><code>jQuery(document).ready(function($){
  $('#sidebar').affix({
        offset: {
          top: 245
        }
  });
  
  var $body   = $(document.body);
  var navHeight = $('.navbar').outerHeight(true) + 10;
  
  $body.scrollspy({
      target: '#leftCol',
      offset: navHeight
  });
  });
  </code></pre>
  
  <p>And here is the error message</p>
  
  <blockquote>
    <p>Uncaught TypeError: $(...).affix is not a function</p>
  </blockquote>
  
  <p>Would anyone happen to know why this issue is occurring?</p>
  
  <p>Thanks</p>