Linked list implementation in java – Singly Linked list

    Linked list is a linear data structure which stores data in nodes. Each node has a link to other node. A linked list has three different types listed as follows.

• ·       Singly Linked list
• ·       Doubly Linked list
• ·       Circular Linked list

Let us implement singly linked list in java.

Logic:

• First, create a node structure.
• It has a data element and link.
• Initialise the data and link in the constructor.
• Define two functions insert() and display().
• ‘insert()’ :
• Create an object for node.
• Check the head pointer is null then, assign the head to new node.
• Create a temp variable. If the temp.link is not null then make the ‘temp’ variable as temp.link.
• ‘display()’:
• Assign the ‘temp’ variable to head.
• ‘temp’ is not null, print the dull.
• ‘main()’ :
• Create a object for SinglyLinkedListEg.
• Call the insert() function to add the data.
• Call the display() function to display the data.

Program:

class SinglyLinkedListEg {

    class Node {

        int data;

        Node link;

        Node(int data) {

            this.data = data;

            this.link = null;

        }

    }

    Node head;

    public void insert(int data) {

        Node newNode1 = new Node(data);

        if (head == null) {

            head = newNode1;

        } else {

            Node temp = head;

            while (temp.link != null) {

                temp = temp.link;

            }

            temp.link = newNode1;

        }

    }

    public void display() {

        Node temp = head;

        while (temp != null) {

            System.out.print(temp.data + " -> ");

            temp = temp.link;

        }

        System.out.println("null");

    }

      public static void main(String[] args) {

        SinglyLinkedListEg s1 = new SinglyLinkedListEg();

        // add data elements to the linked list

        s1.insert(110);

        s1.insert(220);

        s1.insert(300);

        s1.insert(789);

        s1.insert(456);

        // Display the list

        System.out.println("Singly Linked List:");

        s1.display();

    }

}

Output:

Compile and run the program as follows….

C:\raji\blog>javac SinglyLinkedListEg.java

C:\raji\blog>java SinglyLinkedListEg

Singly Linked List:

110 -> 220 -> 300 -> 789 -> 456 -> null

Yes. This is the implementation of Singly Linked list in java. Hope you understand this code. Keep coding!!!