title: What does it mean $ and $$ in javascript?
body: <p>Please explain the meaning of the $ and $$</p>
  
  <p>This is sample code use $ and $$:
  <a href="https://github.com/cytoscape/cytoscape.js-qtip/blob/master/cytoscape-qtip.js" rel="noreferrer">https://github.com/cytoscape/cytoscape.js-qtip/blob/master/cytoscape-qtip.js</a></p>
  
  <p>what mean this code use $:</p>
  
  <pre><code>var $qtipContainer = $('&lt;div&gt;&lt;/div&gt;');
  </code></pre>