1 function LinkedList(){
2 var Node = function(element){
3 this.element = element;
4 this.next = null;
5 };
6
7 var length = 0;
8 var head = null
9
10 this.append = function(element){
11 // 创建一个节点
12 var node = new Node(element);
13 var current = null;
14
15 if (head == null){
16 head = node;
17 }else{
18 current = head;
19 while(current.next){
20 current = current.next;
21 }
22 //找到最后一项，将其next赋为node，建立连接
23 current.next = node;
24 }
25 length++;
26 } //向链表尾部添加一个新的项
27
28 this.insert = function (position, element) {
29 // 检查越界
30 if(position >= 0 && position < length){
31 var node = new Node(element);
32 var current = head;
33 var previous = null
34 var index = 0
35
36 if(position === 0){
37 node.next = current;
38 head = node;
39 }else{
40 // 1 从前往后遍历找到position
41 while(index < position){
42 previous = current;
43 current = previous.next;
44 index++;
45 }
46
47 //通过改变指针，将node链接在previous和current之间
48 previous.next = node;
49 node.next = current;
50
51 // 2 经验证1和2没有区别
52 //while (index++ < position) {
53 // previous = current;
54 // current = current.next;
55 //}
56 //通过改变指针，将node链接在previous和current之间
57 //node.next = current;
58 //previous.next = node;
59 return true;
60 }
61 }else{
62 return false;
63 }
64 }; //向链表特定位置插入一个新的项
65
66 this.removeAt = function (position) {
67 if(position > -1 && position < length){
68 var current = head;
69 var previous = null;
70 var index = 0;
71
72 if (position == 0){
73 head = current.next;
74 }else{
75 while(index < position){
76 previous = current;
77 current = current.next;
78 index++;
79 }
80 previous.next = current.next;
81 }
82 length--;
83 return current.element;
84 }else{
85 return null;
86 }
87 }; //从链表特定位置移除一项
88 this.remove = function (element) {
89 var index = this.indexOf(element);
90 this.removeAt(index);
91 }; //从链表中移除一项
92 this.indexOf = function (element) {
93 var current = head;
94 var index = 0;
95 while(current){
96 if (current.element === element){
97 return index;
98 }
99 current = current.next;
100 index++;
101 }
102 return -1;
103 }; //返回元素在链表中的索引，如果没有则返回-1
104 this.isEmpty = function () {
105 return length === 0;
106 }; //判断链表是否为空
107 this.size = function () {
108 return length;
109 }; //返回链表包含元素个数
110 this.getHead = function () {
111 return head;
112 }; //返回链表第一个元素
113 this.toString = function () {
114 var current = head;
115 var str = "";
116 while(current){
117 current = current.next;
118 str += "," + current.element;
119 }
120 return str.slice(1);
121 }; //只输出元素的值
122 this.print = function () {
123 console.log(this.toString());
124 }; //打印元素的值
125 }
