Convert Doubly Linked List to Array II solution and explanation

"""
# Definition for a Node.
class Node:
    def __init__(self, val, prev=None, next=None):
        self.val = val
        self.prev = prev
        self.next = next
"""


class Solution:
    def toArray(self, node: "Optional[Node]") -> List[int]:
        while node.prev:
            node = node.prev
        ans = []
        while node:
            ans.append(node.val)
            node = node.next
        return ans

/*
// Definition for a Node.
class Node {
    public int val;
    public Node prev;
    public Node next;
};
*/

class Solution {
    public int[] toArray(Node node) {
        while (node != null && node.prev != null) {
            node = node.prev;
        }
        var ans = new ArrayList<Integer>();
        for (; node != null; node = node.next) {
            ans.add(node.val);
        }
        return ans.stream().mapToInt(i -> i).toArray();
    }
}

/**
 * Definition for doubly-linked list.
 * class Node {
 *     int val;
 *     Node* prev;
 *     Node* next;
 *     Node() : val(0), next(nullptr), prev(nullptr) {}
 *     Node(int x) : val(x), next(nullptr), prev(nullptr) {}
 *     Node(int x, Node *prev, Node *next) : val(x), next(next), prev(prev) {}
 * };
 */
class Solution {
public:
    vector<int> toArray(Node* node) {
        while (node && node->prev) {
            node = node->prev;
        }
        vector<int> ans;
        for (; node; node = node->next) {
            ans.push_back(node->val);
        }
        return ans;
    }
};

/**
 * Definition for _Node.
 * class _Node {
 *     val: number
 *     prev: _Node | null
 *     next: _Node | null
 *
 *     constructor(val?: number, prev? : _Node, next? : _Node) {
 *         this.val = (val===undefined ? 0 : val);
 *         this.prev = (prev===undefined ? null : prev);
 *         this.next = (next===undefined ? null : next);
 *     }
 * }
 */

function toArray(node: _Node | null): number[] {
    while (node && node.prev) {
        node = node.prev;
    }
    const ans: number[] = [];
    for (; node; node = node.next) {
        ans.push(node.val);
    }
    return ans;
}

/**
 * Definition for a Node.
 * type Node struct {
 *     Val int
 *     Next *Node
 *     Prev *Node
 * }
 */

func toArray(node *Node) (ans []int) {
	for node != nil && node.Prev != nil {
		node = node.Prev
	}
	for ; node != nil; node = node.Next {
		ans = append(ans, node.Val)
	}
	return
}