how to get single id from array

need help , I am new in laravel framework,here how we can passed the checkpoint id this is my code.

 $data['checkpoints'] = CheckpointTemplate::where('checklist_template_id', $data['checklist']->checklist_template_id)->where('is_flexible',0)->orderby('sort_order', 'asc')->orderby('sort_order', 'asc')->get()->toArray();

this working fine, but here how to passed $data['checkpoint_error_msgs'] = CheckpointErrormsg::where('checkpoint_id',**$data['checkpoints']->id**)-> orderby('error_message', 'asc')->lists('error_message', 'error_message');

via Chebli Mohamed