List Class Implementation

List.js

// Defination of construction function
function List(){
	this.listSize = 0;
	this.pos=0;
	this.dataStore = []; //initialize an empty array to store list elements
	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;
}


// Append
function append(element){
	this.dataStore[this.listSize++] = element;
}

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

// Remove
function remove(element){
	var foundAt = this.find(element);
	if(foundAt > -1){
		this.dataStore.splice(foundAt,1);
		// this.listSize;
		return true;
	}
	return false;
}

// Length
function length(){
	return this.listSize;
}

// toString
function toString(){
	return this.dataStore;
}

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



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

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

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

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

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

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

// currPos
function currPos(){
	return this.pos;
}

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

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




//----------------------------------//
//          Test
//----------------------------------//
// var names = new List();
// names.append("Clayton");
// names.append("Raymond");
// names.append("Cynthia");
// names.append("Jennifer");
// names.append("Bryan");
// names.append("Danny");
// names.front();
// console.log(names.getElement()); // displays Clayton