DATA STRUCTURE - Persistent Data structure

In computing, a persistent data structure is a data structure that always preserves the previous version of itself when it is modified.

https://en.wikipedia.org/wiki/Persistent_data_structure

DATA STURCTURE - Singly and Dobly linked list

Basic explanation Singly and Dobly Linked list https://en.wikipedia.org/wiki/Linked_list

Dobly Linked list  https://en.wikipedia.org/wiki/Doubly_linked_list

JavaScript - collection method explaned

http://www.thatjsdude.com/interview/linkedList.html