DECLARE 
   l_fav   json_object_t; 
   l_num   NUMBER; 
BEGIN 
   l_fav := json_object_t ('{"favorite_flavor":"","qwe":"55123"}'); 
    
   l_fav.on_error (3); 
    
   l_num := l_fav.get_number ('favorite_flavor'); 
    
   DBMS_OUTPUT.put_line ('Number = ' || l_num); 
    
   l_fav := json_object_t ('{"favorite_flavor":""}'); 
    
   l_num := l_fav.get_number ('favorite_flavor'); 
    
   DBMS_OUTPUT.put_line ('Number = ' || l_num); 
    
END;