A linked list is a linear data structure, in which the elements are not sorted at contiguous memory locations. The elements in a linked list are linked using pointers:A singly linked list consists of nodes where each node contains a data field and a reference (link) to the next node in the list.A doubly linked list is a variant of a singly linked list, in which each node contains a data field and two references (links): one reference to the previous node in the list and one reference to the next node in the list.In Java, a singly linked list can be implemented using the `LinkedList` class, and a doubly linked list can be implemented using the `java.util.LinkedList` class.Both singly and doubly linked lists have their own advantages and disadvantages. Singly linked lists are simpler to implement and require less memory overhead than doubly linked lists. However, doubly linked lists allow for more efficient insertion and deletion operations than singly linked lists.
Implementing a singly or doubly linked list in Java is a common coding challenge, often encountered in coding interviews. It tests a candidate’s understanding of data structures and algorithms, as well as their ability to implement them efficiently. Being able to implement a linked list in Java is a valuable skill for any programmer, as linked lists are used in a wide variety of applications, such as implementing queues, stacks, and graphs.
