title: jquery extend vs angular extend
body: <p>What is the difference between these two extend functions? </p>
  
  <pre class="lang-js prettyprint-override"><code>  angular.extend(a,b);
    $.extend(a,b);
  </code></pre>
  
  <p>While the jquery.extend is well documented the angular.extend lacks details and the comments there provide no answers. (<a href="https://docs.angularjs.org/api/ng/function/angular.extend" rel="noreferrer">https://docs.angularjs.org/api/ng/function/angular.extend</a>).</p>
  
  <p>Does angular.extend also provide deep copy?</p>