title: How to remove pointers after a ParseObject is deleted? Parse.com
body: <p>I have 2 classes in Parse, a User class and a Group class. The User class has a column that holds an array of pointers to the group class. Suppose I delete a Group object, how can I subsequently remove all pointers in the User class.</p>
  
  <p>I know this is achievable in Parse Cloud code using the <code>beforeDelete</code> trigger but I'm not sure how to implement it. Any help is appreciated.  </p>