Reading Time: 7 minutes
Published: 26 September 2025
You want to write simple and error-free linked list code that works reliably for insertions and deletions without wasting time on tricky conditions. With normal linked lists, you often have to check if the list is empty, handle special cases for the first node, and fix bugs from subtle pointer mistakes.
A Header Linked List solves this by providing a fixed starting point. This guide will show you how this fixed-anchor approach works, explore its five key types, detail its real-world use cases, and give you a full C program to practice with, helping you ace your projects and interviews.
A Header Linked List is a specialized linked list that uses a dummy header node at the very beginning. This special node does not store data but serves as a permanent, fixed reference point for the entire structure.
This structure fundamentally changes how you perform operations:
There are 5 types of header linked lists:
Each node in a linked list, which is a linear data structure, has both data and a reference (or link) to the node after it in the sequence. These nodes are kept in memory. Linked lists can be classified into singly linked lists and doubly linked lists, based on how the nodes are linked to each other.
A grounded header linked list is a linked list where the last node points to null. It is a type of header-linked list with a special node at the beginning, called the header node. The header node allows access to all nodes in the list and does not need to represent the same data type as other nodes.
A circular header linked list is a header-linked list that has a header node at the beginning of the list and the last node points to the header node. This header node is a special node the header node gives access to all the nodes in the linked list.
A Two-Way Header Linked List is a variation of the doubly linked list where there is a special header node that serves as an anchor for both directions (forward and backward) of traversal.
A Circular Two-Way Header Linked List combines features from both circular lists and doubly linked lists. It has a header node, and both the next and previous pointers of the nodes are used. Additionally, the list is circular, meaning the last node's next pointer links back to the header, and the first node's previous pointer links back to the header as well.
A Header Linked List uses a dummy start node to simplify all major list operations.
The five primary types are categorized by their links:
Bottom Line:
Header-linked lists trade a little extra memory for code that is more reliable, easier to maintain, and faster to debug.
Here are the applications of the header linked list:
Bottom Line:
Header-linked lists are ideal for use cases where frequent updates and safe, repeatable operations are required — from student projects to operating system kernels.
#include <stdio.h>
#include <stdlib.h>
// Definition of the node structure
typedef struct Node {
int data;
struct Node* next;
} Node;
// Definition of the linked list with a header node
typedef struct LinkedList {
Node* header;
} LinkedList;
// Function to create a new node
Node* create_node(int data) {
Node* new_node = (Node*)malloc(sizeof(Node));
if (new_node == NULL) {
printf("Memory allocation failed!\n");
exit(1);
}
new_node->data = data;
new_node->next = NULL;
return new_node;
}
LinkedList* create_list() {
LinkedList* list = (LinkedList*)malloc(sizeof(LinkedList));
if (list == NULL) {
printf("Memory allocation failed!\n");
exit(1);
}
// Creating a header node without any meaningful data (data = -1)
list->header = create_node(-1);
return list;
}
// You add a node to the end of the linked list using this function.
void insert_end(LinkedList* list, int data) {
Node* new_node = create_node(data);
Node* temp = list->header;
// Traverse to the last node
while (temp->next != NULL) {
temp = temp->next;
}
// Insert the new node at the end
temp->next = new_node;
}
// Function to display the list
void display_list(LinkedList* list) {
Node* temp = list->header->next; // Skip the header node
while (temp != NULL) {
printf("%d -> ", temp->data);
temp = temp->next;
}
printf("NULL\n");
}
// Function to delete a node by its value
void delete_node(LinkedList* list, int value) {
Node* temp = list->header;
while (temp->next != NULL && temp->next->data != value) {
temp = temp->next;
}
if (temp->next != NULL) {
Node* to_delete = temp->next;
temp->next = temp->next->next;
free(to_delete);
printf("Node with value %d deleted.\n", value);
} else {
printf("Node with value %d not found.\n", value);
}
}
// Function to free the entire list
void free_list(LinkedList* list) {
Node* temp = list->header;
while (temp != NULL) {
Node* next = temp->next;
free(temp);
temp = next;
}
free(list);
}
int main() {
// Create a new list
LinkedList* list = create_list();
// Insert elements into the list
insert_end(list, 10);
insert_end(list, 30);
insert_end(list, 40);
insert_end(list, 50);
// Display the list
printf("Linked List: ");
display_list(list);
// Delete a node
delete_node(list, 30);
printf("Linked List after deletion: ");
display_list(list);
// Free the list memory
free_list(list);
return 0;
}
The Linked List: 10 -> 30 -> 40 -> 50 -> NULL
Node with value 30 deleted.
The Linked List after deletion: 10 -> 40 -> 50 -> NULL
The code uses a Header Linked List to make operations simple and consistent.
The create_list() function immediately sets up a dummy header node (list->header), which acts as a fixed reference point, ensuring the list is never "empty."
Key Implementation Details:
insert_end() and delete_node() start traversal from the header. This makes the header a permanent predecessor to the first data node, eliminating complex if statements typically needed when modifying the list's beginning.display_list() starts at list->header->next to skip the dummy node.This approach exchanges minimal memory for cleaner, safer code.
The header node in the linked list is used to simplify operations such as insertion, deletion, and traversal. It eliminates the need to check for any special cases such as an empty list.
Yes, header nodes are useful in circular or doubly linked lists to simplify the traversal and manipulation of the nodes.
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Source: NxtWave - Original Article