How to Create Custom Linked List Class, Insert Values and Print it in Java

Implementing a Custom Linked List Class from Scratch in Java

 

In this article, we will seen

• How to create Node Class

• Create Insert method and Add data in Custom Linked list Class

• Print All elements of Linked list

Linked list is linear data structure, means it stores values in linear manner but like Arrays it does not store elements at contiguous location.

Linked list class represent as node and node contains value and reference of next and previous node.

You can learn about Linked list class in details :

List interface and Linked list class 

Lets start with creating singly custom linked list class.

Step 1 : Create Node class

class Node {
    
    //Data in the current node
    int value;
    //Reference for the next node
    Node next;

    Node(int value) {
        this.value = value;
    }
}

Step 2 : Create Custom Linked list class, Add insert() and printList() methods

class CustomLinkedList {
    
    Node head;

    public void insert(int value) {
        Node newNode = new Node(value);
        
        if (head == null) {
            head = newNode;
        } else {
            Node node = head;
            while(node.next != null) {
                node = node.next;
            }
            node.next = newNode;
        }
    }

    public static void printList(CustomLinkedList list) {
        
        Node currNode = list.head;
    
        // Traverse through the LinkedList
        while (currNode != null) {
            // Print the data at current node
            System.out.print(currNode.value + " ");
    
            // Go to next node
            currNode = currNode.next;
        }
    }
}

Step 3 : Create Main class and Call CustomeLinkedList class insert() and printList() method

import java.util.Scanner;

public class Example {

    public static void main(String[] args) {
       
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Size of LinkedList");
        int size = sc.nextInt();
       
        System.out.println("Enter Data in LinkedList");
       
        // Creating CustomLinkedList object and storing Node
        CustomLinkedList obj = new CustomLinkedList();
        for (int i = 0; i < size; i++) {
             obj.insert(sc.nextInt());
        }
 
        // Print Linked list elements
        obj.printList(list);
    }

}

Output :

Enter Size of LinkedList
6
Enter Data in LinkedList
1 2 3 6 5 4

1 2 3 6 5 4
________________________

Enter Size of LinkedList
10
Enter Data in LinkedList
10 2 30 60 8 55 9 66 94 25

10 2 30 60 8 55 9 66 94 25 

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• Guide to Collection framework in Java with Examples
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