class Person 
{
   private BankAccount account;

   Person(BankAccount account)
   {
      this.account = account;
   }

   public Person someMethod(Person person)
   {
     //Why accessing private field is possible?

     BankAccount a = person.account;
   }
}

请忘记设计。我知道OOP指定私有对象是该类的私有对象。我的问题是，为什么将OOP设计为使私有字段具有类级别的访问权限而不具有对象级别的访问权限？