linked-list.js

function LinkedList(){
	this.head = null;
}

LinkedList.prototype.append = function(data){
	var newNode = {
		data :  data,
		next : this.head //  Since the new node is going to be the head, assigning existing head reference to next property
	}
	this.head = newNode;
}


LinkedList.prototype.prepend = function(x){
	var newNode = {
			data : x,
			next : null // Since its a last node, next value will always be null
	}
	// If its a empty list, set the head value as new node and return 
	if(this.head ==  null){
		this.head = newNode;
		return;
	}

	// traverse throught the list till the last node is reached. 
	// to begin with traversing set the current as this.head which is nothing but the first element in the list;
	var current = this.head;
	// if current.next is null, it means loop has reached the last element and current is the last element.
	while(current.next != null){
		current = current.next;
	}
	// Assign the current.next to newNode
	current.next = newNode;
}

LinkedList.prototype.print = function(){
	var arr = [];
	var current = this.head;
	while(current !== null){
		arr.push(current.data)
		current = current.next;
	}
	console.log("LinkedList values : ", arr);
}