LinkedList.js

var Node = function(value) {
	this.value = value;
	this.next=null;
	return this;
};

var LinkedList = function(node){
	this.head = node;
	return this;
};

LinkedList.prototype.insertEnd = function(newNode, currentNode) {
	var currentNode = currentNode || this.head;
		
	if(currentNode.next !== null) {
		return this.insertEnd(newNode, currentNode.next);
	} else {
		currentNode.next = newNode;
	}
};

LinkedList.prototype.insertBeginning = function(newNode) {
	newNode.next = this.head;
	this.head = newNode;
};

LinkedList.prototype.search = function(searchValue, currentNode) {
	var currentNode = currentNode || this.head;
	if(currentNode.value == searchValue) {
		console.log("true");
		return true;
	} else if(currentNode.next !== null) {
		return this.search(searchValue, currentNode.next);
	}
	console.log("not found");
	return false;
};
LinkedList.prototype.remove = function(deleteValue, currentNode, parentNode) {
	currentNode = currentNode || this.head;
	if(currentNode.value === deleteValue) {
		if(currentNode.next !== null) {
			parentNode.next = currentNode.next;
		} else {
			parentNode.next = null;	
		}				
	} else if(currentNode.next !== null) {
		return this.remove(deleteValue, currentNode.next, currentNode);
	}
};

// Improvements from: http://codereview.stackexchange.com/a/31522/29315
LinkedList.prototype.search = function(searchValue, currentNode) {
	var currentNode = currentNode || this.head;
	if(currentNode.value == searchValue) {
		console.log("true");
		return true;
	} else if(currentNode.next !== null) {
		return this.search(searchValue, currentNode.next);
	}
	console.log("not found");
	return false;
};

(function(){
	// LinkedList Example
	var linkedList = new LinkedList(new Node("oldHead"));
	linkedList.insertEnd(new Node(2));
	linkedList.insertEnd(new Node("cat"));
	linkedList.insertEnd(new Node("dog"));
	linkedList.insertEnd(new Node(100));

	linkedList.search("cat");
	console.log('size: '+linkedList.size());
	linkedList.remove("cat");
	console.log('size: '+linkedList.size());
	linkedList.search("cat");
	console.log("current head: "+linkedList.head.value);
	linkedList.insertBeginning(new Node("testBeginningInsert"));
	console.log("current head: "+linkedList.head.value);
	console.log('size: '+linkedList.size());
})();