Java脚本通过递归获取根元素

如何解决Java脚本通过递归获取根元素

我需要获取每个节点的根元素。
我下面有两个功能。
当我运行getRoot时，我得到了undefined。
我认为问题出在递归函数中。

例如：对于节点id=3，我需要{id: 1,name: "Business1"}。

//to get the parent for any node
function getParent(id) {
  const node = this._items.find(
    item => item.parent !== undefined && item.id == id
  );
  return node.parent;
}

//to get the root for the node
function getRoot(parent) {
  console.log(this._items);
  this._items.forEach(element => {
    if (element.id == parent) {
      if (element.parent === undefined) return element;
      else return this.getRoot(element.parent);
    }
  });
}

//constant array
const array = [
  {id: 1,name: "Business1"},{id: 2,name: "Canton1",parent: 1},{id: 3,name: "Branch1",parent: 2},{id: 4,name: "Branch2",{id: 5,name: "Canton2",{id: 6,parent: 5},{id: 7,{id: 8,name: "Canton3",{id: 9,parent: 8},{id: 10,name: "Business2"},parent: 9},{id: 11,parent: 10},{id: 12,{id: 13,{id: 14,parent: 13},{id: 15,{id: 16,{id: 17,parent: 16},{id: 18,];

解决方法

const items = [{ id: 1,name: "Business1" },{ id: 2,name: "Canton1",parent: 1 },{ id: 3,name: "Branch1",parent: 2 },{ id: 4,name: "Branch2",{ id: 5,name: "Canton2",{ id: 6,parent: 5 },{ id: 7,{ id: 8,name: "Canton3",{ id: 9,parent: 8 },{ id: 10,name: "Business2" },parent: 9 },{ id: 11,parent: 10 },{ id: 12,{ id: 13,{ id: 14,parent: 13 },{ id: 15,{ id: 16,{ id: 17,parent: 16 },{ id: 18,parent: 16 }]


const getParent = (id) => {
    const node = items.filter(e => e.id == id)
    if (node.length == 0) return undefined // throw some error here
    let currentNode = node[0]
    return currentNode.parent !== undefined ? getParent(currentNode.parent) : currentNode
}

console.log(getParent(3))

,

let _items = [
    {id: 1,name: "Business1"},{id: 2,parent: 1},{id: 3,parent: 2},{id: 4,{id: 5,{id: 6,parent: 5},{id: 7,{id: 8,{id: 9,parent: 8},{id: 10,{id: 11,name: "Business2"},{id: 12,parent: 11},{id: 13,parent: 12},{id: 14,{id: 15,{id: 16,parent: 15},{id: 17,{id: 18,{id: 19,parent: 18},{id: 20,parent: 18}
];
function findElementById(id) {
    let element_return = false;
    _items.forEach(element => {
        if (id === element.id) {
            element_return = element;
            return true;
        }
    });
    return element_return;
}
function getRoot(parent) {
    element = findElementById(parent);
    if (element) {
        if (typeof (element.parent) !== "undefined") {
            return getRoot(element.parent);
        } else {
            return element.id;
        }
    } else {
        return parent;
    }
}
let test_root = getRoot(3);
console.log(test_root);
console.log(findElementById(test_root));

test_root = getRoot(11);
console.log(test_root);
console.log(findElementById(test_root));