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.