Linked list of js

/* * ??单向链表 * ??Node 类用来表示节点 * ??LinkedList 类提供了插入节点、删除节点、显示列表元素的方法，以及其他一些辅助方法。 */function Node(element) { ???this.element = element; ???this.next = null;};function LList() { ???this.head = new Node("head");};LList.prototype = { ???constructor: LList, ???find: function(item) { ???????var currNode = this.head; ???????while (currNode && currNode.element != item) { ???????????currNode = currNode.next; ???????} ???????return currNode; ???}, ???insert: function(newElement, item) { ???????var newNode = new Node(newElement); ???????var current = this.find(item); ???????newNode.next = current.next; ???????current.next = newNode; ???}, ???display: function() { ???????var currNode = this.head; ???????while (!(currNode.next == null)) { ???????????console.log(currNode.next.element); ???????????currNode = currNode.next; ???????} ???}, ???findPrevious: function(item) { ???????var currNode = this.head; ???????while (!(currNode.next == null) && ???????????(currNode.next.element != item)) { ???????????currNode = currNode.next; ???????} ???????return currNode; ???}, ???remove: function(item) { ???????var prevNode = this.findPrevious(item); ???????if (!(prevNode.next == null)) { ???????????prevNode.next = prevNode.next.next; ???????} ???}};//这个链表还需要优化，当前面element与后面insert定位的element相同时存在问题
//下面例子给予说明var myName = new LList();myName.insert(‘张‘, ‘head‘);myName.insert(‘柠‘, ‘张‘);myName.insert(‘檬‘, ‘柠‘);myName.display(); ?//张，柠，檬var myName = new LList();myName.insert(‘张‘, ‘head‘);myName.insert(‘柠‘, ‘张‘);myName.insert(‘檬‘, ‘柠‘);myName.insert(‘的‘, ‘檬‘);myName.insert(‘柠‘, ‘的‘);myName.insert(‘檬‘, ‘柠‘);myName.display(); ?//张，柠，檬，檬， 的， 柠， 并未按照顺序来 /* ?* ??双向链表 ?* ??Node 类用来表示节点 ?* ??LinkedList 类提供了插入节点、删除节点、显示列表元素的方法，以及其他一些辅助方法。 ?*/function Node(element) { ???this.element = element; ???this.next = null; ???this.previous = null;};LList.prototype = { ???constructor: Node, ???find: function(item) { ???????var currNode = this.head; ???????while (currNode.element != item) { ???????????currNode = currNode.next; ???????} ???????return currNode; ???}, ???insert: function(newElement, item) { ???????var newNode = new Node(newElement); ???????var current = this.find(item); ???????newNode.next = current.next; ???????newNode.previous = current; ???????current.next = newNode; ???}, ???remove: function(item) { ???????var currNode = this.find(item); ???????if (!(currNode.next == null)) { ???????????currNode.previous.next = currNode.next; ???????????currNode.next.previous = currNode.previous; ???????????currNode.next = null; ???????????currNode.previous = null; ???????} ???}, ???findLast: function() { ???????var currNode = this.head; ???????while (!(currNode.next == null)) { ???????????currNode = currNode.next; ???????} ???????return currNode; ???}, ???dispReverse: function() { ???????var currNode = this.head; ???????currNode = this.findLast(); ???????while (!(currNode.previous == null)) { ???????????console.log(currNode.element); ???????????currNode = currNode.previous; ???????} ???}, ???display: function() { ???????var currNode = this.head; ???????while (!(currNode.next == null)) { ???????????console.log(currNode.next.element); ???????????currNode = currNode.next; ???????} ???}};//双向链表也存在上述问题//循环列表function Node(element) { ???this.element = element; ???this.next = null;};function LList() { ???this.head = new Node("head"); ???this.head.next = this.head;};LList.prototype = { ???constructor: LList, ???find: function(item) { ???????var currNode = this.head; ???????while (currNode && currNode.element != item && !(currNode.next.element == "head")) { ???????????currNode = currNode.next; ???????} ???????return currNode.element == item ? currNode : null; ???}, ???insert: function(newElement, item) { ???????var newNode = new Node(newElement); ???????var current = this.find(item); ???????newNode.next = current.next; ???????current.next = newNode; ???}, ???display: function() { ???????var currNode = this.head; ???????while (!(currNode.next == null) && !(currNode.next.element == "head")) { ???????????console.log(currNode.next.element); ???????????currNode = currNode.next; ???????} ???}, ???findPrevious: function(item) { ???????var currNode = this.head; ???????while (!(currNode.next == null) && !(currNode.next.element == "head") && (currNode.next.element != item)) { ???????????currNode = currNode.next; ???????} ???????return currNode; ???}, ???remove: function (item) { ???????var prevNode = this.findPrevious(item); ???????if (!(prevNode.next == null)) { ???????????prevNode.next = prevNode.next.next; ???????} ???}};