superClass 的私有成员是否由子类继承... Java? [英] Are the private members of superClass inherited by a subClass... Java?

问题描述

我经历过这个:

子类是否继承私有字段?

但我还是一头雾水……

我说的是只继承而不是访问.我知道他们在课堂之外是不可见的.

I'm talking about inheriting only and not accessing. I know that they aren't visible out side class.

但是子类的对象是否在超类中拥有自己的私有成员的副本?

But does the subclass' object has it's own copies of those private members in super class?

例如...

class Base {
    private int i;
}

class Derived extends Base {
    int j;
}

现在，

Base b = new Base();
Derived d = new Derived();

int 的大小为 4

现在，

b 的大小是否为 4，d 的大小是否为 8

Will the size of b be 4 and size of d be 8

或

d 的大小也只有 4 吗?

size of d will also be 4 only ?

当然，当我说 b 和 d 时，我指的是堆上的对象，而不是引用.

Of course I'm talking about the objects on the heap when I say b and d and not the references.

更新:我刚刚阅读了 Kathy Sierra & 的 SCJP 书籍伯特......它说他们不是继承的......我发布了这个更新，因为仍然有很多人说是......

UPDATE: I just read in SCJP Book of Kathy Sierra & Bert... It says that they are NOT inherited.... I posted this update since still there are bunch of people saying yes...

推荐答案

是的，子类的实例将拥有父类私有字段的副本.

Yes, instances of the subclass will have copies of a private field of the parent class.

然而，它们对子类不可见，因此访问它们的唯一方法是通过父类的方法.

They will however not be visible to the subclass, so the only way to access them is via methods of the parent class.

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