Get data from meta tags in javascript

get-content-from-meta-tags-in-js.js

<script type='text/javascript'>
  /*
  * Here we try to retreive a data from <meta name="bitly:url" content=""/>
  */
  var BitlyURL = jQuery('meta[property="bitly:url"]').attr('content');
  var url = "";
         if ( typeof BitlyURL  !== 'undefined' ){
     url = BitlyURL;
         }
  else 
    url = "<?= the_permalink(); ?>";
  jQuery(document).ready(function(){
  var ta = document.getElementById('twitter_<?= $post->ID ?>');
  ta.href="https://twitter.com/home/?status=<?php the_title(); ?> - " + url;
var fa = document.getElementById('facebook_<?= $post->ID ?>');
  fa.href="https://www.facebook.com/sharer.php?u=" + url + "&amp;t=<?php the_title(); ?>";
</script>