<script>function Node(element) {  this.element = element;//當前節點的元素  this.next = null;//下一個節點鏈接}function List() {  this.head = new Node("head");//頭節點  this.find = find;//查找節點  this.insert = insert;//插入節點  this.remove = remove;//刪除節點  this.display = display;//顯示鏈表  this.findPrevious = findPrevious; //查找前一個節點}//下面的函數是操作方法：對應List類構造函數中的名稱//查找給定節點function find(item) {  var currNode = this.head;  while(currNode.element != item) {    currNode = currNode.next;  }  return currNode;}//向鏈表插入一個節點function insert(newElement,item) {  var newNode = new Node(newElement);  var current = this.find(item);  if(current == null)    return console.log("can't find the item");  newNode.next = current.next;  current.next = newNode;}//刪除節點function remove(item) {  var prevNode = this.findPrevious(item);  if(prevNode.next != null)    prevNode.next = prevNode.next.next;}//從鏈表中刪除節點時，我們先要找個待刪除節點的前一個節點，找到后，我們修改它的 next 屬性，使其不在指向待刪除的節點，而是待刪除節點的下一個節點。那么，我們就得需要定義一個 findPrevious 方法遍歷鏈表，檢查每一個節點的下一個節點是否存儲待刪除的數據。如果找到，返回該節點，這樣就可以修改它的 next 屬性了。//查找帶刪除節點的前一個節點function findPrevious(item) {  var currNode = this.head;  while(currNode.next != null && currNode.next.element != item) {    currNode = currNode.next;  }  return currNode;}//顯示鏈表元素function display() {  var current = this.head;  while(current.next != null) {    console.log(current.next.element);    current = current.next;  }}/** * @param {Node} l1 * @param {Node} l2 * @return {Node} */var mergeTwoLists = function(l1, l2) {  // 模仿鏈表的數據結構  var mergedHead = { element : -1, next : null },    cur = mergedHead;  while (l1 && l2){    if(l1.element <= l2.element){      cur.next = l1;      l1 = l1.next;    }    else {      cur.next = l2;      l2 = l2.next;    }    cur = cur.next;  }  cur.next = l1 || l2  return mergedHead.next;};let list1 = new List();list1.insert(1,'head');list1.insert(2,1);list1.insert(4,2);console.log(list1.display());let list2 = new List();list2.insert(1,'head');list2.insert(3,1);list2.insert(4,3);console.log(list2.display());console.log(mergeTwoLists(list1.head,list2.head))</script>