java - 子类中扩展子类的 super() 构造函数？

Question

我不太确定我的问题措辞是否正确，但我对这些代码行感到困惑。

public class First {
    public String name() {
        return "First";
    }
}

public class Second extends First {
    public void whoRules() {
        System.out.print(super.name() + " rules");
        System.out.println(" but " + name() + " is even better");
    }
    public String name() {
        return "Second";
    }
}

public class Third extends Second {
    public String name() {
        return "Third";
    }
}

Second varSecond = new Second();
Third varThird = new Third();
varSecond.whoRules();
varThird.whoRules();

当上面的执行时，它打印出

First rules but second is even better

First rules but third is even better

为什么不是:

First rules but second is even better

Second rules but third is even better

一个子类可以是另一个类的父类(super class)吗？或者只能有一个(父类(super class))？ (使用上面的示例代码) 我知道 First 是 Second 的父类(super class)，但是 Second 是 Third 的父类(super class)吗？ 或者 First 是 Third 的父类(super class)？

如果有 10 个类相互扩展(第二个首先扩展，第三个第二个扩展，等等)所有这些类的父类(super class)是否都是 First？)

Answer 1

Why wouldn't it be: ... "Second rules but third is even better"

因为类Second中的super.name()引用的是Second的父类(super class)，而不是实例的父类(super class)。

来自Java Language Specification : super.Identifier 的形式引用当前对象的标识符字段，但当前对象被视为当前类的父类(super class)的实例。

Can a subclass be a superclass for another class?

是的。

Or can there only be one(superclass)?

每个类最多可以有一个直接父类(super class)，而父类(super class)又可以有它的父类(super class)，等等。

(Using example code above) I understand that First is a superclass for Second, but is Second a superclass for Third? Or is First the superclass for Third?

First 和 Second 都是 Third 的父类(super class)。

Second 是 Third 的直接父类(super class)。