Queue.js

function Queue() {
	this.length = 0; // I chose this over a for loop in the method getLength because I thought it might be faster. I think the trade off here is that it adds one extra step every dequeue and enqueue rather than spending n steps every method call for getLength.
	this.head = null;
	this.tail = null;
}

Queue.prototype.enqueue = function(n) {
	if(this.length > 0) {
		this.tail.setNextNode(n);
		this.tail = n
	}
	else {
		this.head = n;
		this.tail = n;
	}
	this.length++;
}


Queue.prototype.dequeue = function() {
	if(this.tail == null){
		this.head = null;
	}
	else {
		var pimple = this.head // "pimple" gets popped
		this.head = pimple.getNextNode();
		pimple.setNextNode(null);
		this.length--;
	}
	return pimple;
}

Queue.prototype.peek = function() {
	return this.head;
}

Queue.prototype.getLength = function() {
	return this.length; // 1 step rather than many as in a for loop.
}