This will be used as the starting point to our linked list. The head variable is created and assigned NULL. Creating an empty listĪn empty list has to be created before performing any other operations. The few basic operations in a linked list including adding, deleting and modifying. This is used to keep track of the list beginning and helps during the traversing operations. The head node is used to point to the first node in a linked list.

newNode->next About the head pointer node Similarly, the link to the next Node in the list can be accessed by using the arrow character to the *next member of the structure. The data stored in this Node can be accessed by using the arrow character (->) to the data member of the structure. struct NodeĪ new Node is created first with the desired variable name. This type of a structure is called a self-referential structure where one member of the structure points to the structure of its kind. In C, the node is defined as a structure. The data is not just limited to one value, one can define any number of pieces of information to be stored in each node.

For simplicity, we will consider a Node where the data is a single integer. The Node contains 2 parts, one that is the data itself and the other which references the next node in the sequence. Every time a loop traverses through the array, it checks for this NULL condition to know if the end of the linked list is there.

This specifies that the list has ended with no more nodes to traverse to. The last node always points to NULL in a singly-linked list. To access the last element, it is always required to traverse the whole list to the end. This means that the list can only be traversed from the beginning to the end in one direction. This is the most common type of linked list, where each node has one pointer to the next node in the sequence. The 3 most common types of a linked list are: Types of Linked ListsĪ linked list is designed depending on its use. Each type of list has specific properties and its own merits regarding the list operations. Each element hence takes slightly more memory than an array.įor the linked list to be created, we need to define a node first depending on the type of linked list we want to create.

Memory Usage of each node: The nodes that hold the data need extra memory to hold the pointer to the next node.

One has to go through the links searching for the element required.

Only sequential access: As the data is linked together through nodes, any node can only be accessed by the node linking to it, hence it is not possible to randomly access any node.

There are some disadvantages of using linked lists when compared to arrays though. In contrast, one has to move over all the memory locations while dealing with arrays so that they are in order.

Efficient Insertion and Deletion: A quick manipulation of the links between the nodes allows for a constant time taken for insertion and deletion.

In comparison, an array can only be defined once of a specific size, and then further cannot be extended or shrunk down accordingly. There is no wastage of memory for unused locations.

The memory locations to store the nodes are allocated dynamically when each node is created. Not fixed in size: A linked list is not fixed in size.The 2 advantages of a linked list over an array are: Each person can be seen as a Node who knows the link to the next person. If person A knows person B and person B knows person C, person C could be reached from person A through this linked connection. The linked list can be used to store data similar to arrays but with several more advantages.

Singly linked list