有没有办法更改此关键字引用的对象？

Question

I was wondering if there was a way to do what it says in the title. As an example I have code below:

public List<Shape> path() {
    List<Shape> path = new ArrayList<Shape>();
    path.add(0, this);
    while (this.parent != null) {
        path.add(0, this.parent);
        this = this.parent;
    }
    return path;
}

I want to find a legal way of doing this = this.parent so that I can keep adding the parents to the arraylist until there are no more parents. Is it possible?

Thanks.

Answer 1

No, it's not possible. this is bound to the current object, but nobody stops you from using other reference names like currentNode or whatever that you first initialize as this ( currentNode = this ) and then assign the parents to it: currentNode = currentNode.parent .

Answer 2

You can change the state of the object which is referred by this ,

But you can't make this point to some other object,

this is final

For your case you can create a local reference and operate on it

Answer 3

Assing this to variable of the correct type before the while and use that variable.

public List<Shape> path() {
    List<Shape> path = new ArrayList<Shape>();
    path.add(0, this);

    SomeVar node = this;

    while (node.parent != null) {
      path.add(0, node.parent);
      node = node.parent;
    }
   return path;
}