linked_list.js

/* LinkedList */
class LinkedList {
    constructor() {
        var length = 0;
        var head = null;
        class Node {
            constructor(element) {
                this.element = element;
                this.next = null;
            }
        }
        this.size = function () {
            return length;
        };
        this.head = function () {
            return head;
        };
        this.add = function (element) {
            var node = new Node(element);
            if (head === null) {
                head = node;
            }
            else {
                var currentNode = head;
                while (currentNode.next) {
                    currentNode = currentNode.next;
                }
                currentNode.next = node;
            }
            length++;
        };
        this.remove = function (element) {
            var currentNode = head;
            var previousNode;
            if (currentNode.element === element) {
                head = currentNode.next;
            }
            else {
                while (currentNode.element !== element) {
                    previousNode = currentNode;
                    currentNode = currentNode.next;
                }
                previousNode.next = currentNode.next;
            }
            length--;
        };
        this.isEmpty = function () {
            return length === 0;
        };
        this.indexOf = function (element) {
            var currentNode = head;
            var index = -1;
            while (currentNode) {
                index++;
                if (currentNode.element === element) {
                    return index;
                }
                currentNode = currentNode.next;
            }
            return -1;
        };
        this.elementAt = function (index) {
            var currentNode = head;
            var count = 0;
            while (count < index) {
                count++;
                currentNode = currentNode.next;
            }
            return currentNode.element;
        };
        this.addAt = function (index, element) {
            var node = new Node(element);
            var currentNode = head;
            var previousNode;
            var currentIndex = 0;
            if (index > length) {
                return false;
            }
            if (index === 0) {
                node.next = currentNode;
                head = node;
            }
            else {
                while (currentIndex < index) {
                    currentIndex++;
                    previousNode = currentNode;
                    currentNode = currentNode.next;
                }
                node.next = currentNode;
                previousNode.next = node;
            }
            length++;
        };
        this.removeAt = function (index) {
            var currentNode = head;
            var previousNode;
            var currentIndex = 0;
            if (index < 0 || index >= length) {
                return null;
            }
            if (index === 0) {
                head = currentNode.next;
            }
            else {
                while (currentIndex < index) {
                    currentIndex++;
                    previousNode = currentNode;
                    currentNode = currentNode.next;
                }
                previousNode.next = currentNode.next;
            }
            length--;
            return currentNode.element;
        };
    }
}
  
  var conga = new LinkedList();
  conga.add('Kitten');
  conga.add('Puppy');
  conga.add('Dog');
  conga.add('Cat');
  conga.add('Fish');
  console.log(conga.size());
  console.log(conga.removeAt(3));
  console.log(conga.elementAt(3));
  console.log(conga.indexOf('Puppy'));
  console.log(conga.size());