title: Firebase always return null after the for each loop
body: <p>I want to extract database from <code>Firebase</code>. In for each loop, it shows me the description from <code>database</code> but after the for each loop when I check it again for that description, it shows me <code>null</code> and not only for <code>description</code> but for all other values also. Here is the code for extracting data from <code>Firebase</code>. It doesn't shows any kind of error. Help me.</p>
  
  <pre><code>public void getDatafromFirebase(){
          reference.addValueEventListener(new ValueEventListener() {
              @Override
              public void onDataChange(DataSnapshot dataSnapshot) {
                  DataSnapshot Videoreference = dataSnapshot.child("Videos");
                  for (DataSnapshot videoschild : Videoreference.getChildren()){
                      DataSnapshot description = videoschild.child("Description");
                      DataSnapshot duration = videoschild.child("Duration");
                      DataSnapshot title = videoschild.child("Title");
                      DataSnapshot thumbnail = videoschild.child("Thumbnail");
                      details.setDescription(String.valueOf(description.getValue()));
                      details.setDuration(String.valueOf(duration.getValue()));
                      details.setTitle(String.valueOf(title.getValue()));
                      details.setThumbnail(String.valueOf(thumbnail.getValue()));
                      Log.e("details",details.description);
                      list.add(details);
                  }
                  Log.e("Size",list.get(0).description);
                  adapter.notifyDataSetChanged();
              }
  
              @Override
              public void onCancelled(DatabaseError databaseError) {
                  Toast.makeText(getActivity(), databaseError.getMessage(), Toast.LENGTH_SHORT).show();
              }
          });
      }
  </code></pre>