Example 1: Java program to implement LinkedList
class LinkedList { // create an object of Node class // represent the head of the linked list Node head; // static inner class static class Node { int value; // connect each node to next node Node next; Node(int d) { value = d; next = null; } } public static void main(String[] args) { // create an object of LinkedList LinkedList linkedList = new LinkedList(); // assign values to each linked list node linkedList.head = new Node(1); Node second = new Node(2); Node third = new Node(3); // connect each node of linked list to next node linkedList.head.next = second; second.next = third; // printing node-value System.out.print("LinkedList: "); while (linkedList.head != null) { System.out.print(linkedList.head.value + " "); linkedList.head = linkedList.head.next; } } } Output
LinkedList: 1 2 3
In the above example, we have implemented the singly linked list in Java. Here, the linked list consists of 3 nodes.
Each node consists of value and next. The value variable represents the value of the node and the next represents the link to the next node.
To learn about the working of LinkedList, visit LinkedList Data Structure.
Example 2: Implement LinkedList using LinkedList class
Java provides a built LinkedList class that can be used to implement a linked list.
import java.util.LinkedList; class Main { public static void main(String[] args){ // create a linked list using the LinkedList class LinkedList<String> animals = new LinkedList<>(); // Add elements to LinkedList animals.add("Dog"); // add element at the beginning of linked list animals.addFirst("Cat"); // add element at the end of linked list animals.addLast("Horse"); System.out.println("LinkedList: " + animals); // access first element System.out.println("First Element: " + animals.getFirst()); // access last element System.out.println("Last Element: " + animals.getLast()); } } Output
LinkedList: [Cat, Dog, Horse] First Element: Cat Last Element: Horse
In the above example, we have used the LinkedList class to implement the linked list in Java. Here, we have used methods provided by the class to add elements and access elements from the linked list.
Notice, we have used the angle brackets (<>) while creating the linked list. It represents that the linked list is of the generic type.