Generic type in inner class

问题

I have an outer class (LinkedStack<T>) that has an inner node class. Is it necessary to declare the inner Node class with the same generic like

private Node<T>

as opposed to

private Node

or does it not make any difference?

回答1:

If the inner class is a static class then yes, otherwise no.

I.e.:

class LinkedStack<T> {
    // references to T refer to LinkedStack's T.

    static class Node<T> {
        // references to T refer to Node's T.
        T data;
    }

    // ...
    Node<T> node;
}

or:

class LinkedStack<T> {
    // references to T refer to LinkedStack's T.

    class Node {
        // references to T refer to LinkedStack's T.
        T data;
    }

    // ...
    Node node;
}

来源：https://stackoverflow.com/questions/42817415/generic-type-in-inner-class