How to implement list data structure using javascript

list.js

function List() {
	this.listSize = 0;
	this.pos = 0;
	this.dataSource = [];
	this.clear = clear;
	this.find = find;
	this.toString = toString;
	this.insert = insert;
	this.append = append;
	this.remove = remove;
	this.front = front;
	this.end = end;
	this.prev = prev;
	this.next = next;
	this.length = length;
	this.currPos = currPos;
	this.moveTo = moveTo;
	this.getElement = getElement;
	this.contains = contains;

	function append(element) {
		this.dataSource[this.listSize++] = element;
	}

	function find(element) {
		for(var i = 0; i < this.dataSource.length; ++i) {
			if(this.dataSource[i] == element) return i;
		}
		return -1;
	} //find

	function remove(element) {
		var findAt = this.find(element);
		if (findAt > -1) {
			this.dataSource.splice(findAt, 1);
			--this.listSize;
			return true;
		}
		return false;
	}

	function length() {
		return this.listSize;
	}

	function toString() {
		return this.dataSource;
	}

	function insert(element, after) {
		var insertPos = this.find(after);
		if(insertPos > -1) {
			this.dataSource.splice(insertPos, 0, element);
			++this.listSize;
			return true;
		}
		return false;
	} //insert

	function clear() {
		delete this.dataSource;	
		this.dataSource = [];
		this.listSize = this.pos = 0;
	}

	function contains(element) {
		for(var i = 0; i < this.dataSource.length; ++i) {
			if(this.dataSource[i] == element) return true;
		}
		return false;
	} //contains

	function front() {
		this.pos = 0;
	}

	function end() {
		this.pos = this.listSize - 1;
	}

	function prev() {
		if(this.pos > 0) --this.pos;
	}

	function next() {
		if(this.pos < this.listSize-1) ++this.pos;
	}

	function currPos() {
		return this.pos;
	}

	function moveTo(position) {
		this.pos = position;
	}

	function getElement() {
		return this.dataSource[this.pos];
	}
}

var names = new List();
names.append('ada');
names.append('bob');
names.append('clark');
// console.log(names.toString());
// names.front();
// console.log(names.getElement());
// names.next();
// console.log(names.getElement());

// interate a list
console.log(names.length());
for(names.front(); names.currPos() < names.length(); names.next()) {
	console.log(names.getElement());
}