Iterate or Loop Through Elements LinkedList in Java Example

In this post, we will learn different ways to iterate over a Java LinkedList with an example.

Iterate or Loop Through Elements LinkedList in Java Example


package com.javaguides.collections.linkedlistexamples;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.ListIterator;

public class IterateOverLinkedListExample {
    public static void main(String[] args) {
        LinkedList < String > progLangs = new LinkedList < > ();

        progLangs.add("C");
        progLangs.add("C++");
        progLangs.add("Core Java");
        progLangs.add("Java EE");
        progLangs.add("Spring Framework");
        progLangs.add("Hibernate Framework");

        System.out.println("=== Iterate over a LinkedList using Java 8 forEach and lambda ===");
        progLangs.forEach(name - > {
            System.out.println(name);
        });


        System.out.println("\n=== Iterate over a LinkedList using iterator() ===");
        Iterator < String > iterator = progLangs.iterator();
        while (iterator.hasNext()) {
            String speciesName = iterator.next();
            System.out.println(speciesName);
        }

        System.out.println("\n=== Iterate over a LinkedList using iterator() and Java 8 forEachRemaining() method ===");
        iterator = progLangs.iterator();
        iterator.forEachRemaining(speciesName - > {
            System.out.println(speciesName);
        });

        System.out.println("\n=== Iterate over a LinkedList using descendingIterator() ===");
        Iterator < String > descendingIterator = progLangs.descendingIterator();
        while (descendingIterator.hasNext()) {
            String speciesName = descendingIterator.next();
            System.out.println(speciesName);
        }


        System.out.println("\n=== Iterate over a LinkedList using listIterator() ===");
        // ListIterator can be used to iterate over the LinkedList in both forward and backward directions
        // In this example, we start from the end of the list and traverse backwards
        ListIterator < String > listIterator = progLangs.listIterator(progLangs.size());
        while (listIterator.hasPrevious()) {
            String speciesName = listIterator.previous();
            System.out.println(speciesName);
        }

        System.out.println("\n=== Iterate over a LinkedList using simple for-each loop ===");
        for (String name: progLangs) {
            System.out.println(name);
        }
    }
}

Output

=== Iterate over a LinkedList using Java 8 forEach and lambda ===
C
C++
Core Java
Java EE
Spring Framework
Hibernate Framework

=== Iterate over a LinkedList using iterator() ===
C
C++
Core Java
Java EE
Spring Framework
Hibernate Framework

=== Iterate over a LinkedList using iterator() and Java 8 forEachRemaining() method ===
C
C++
Core Java
Java EE
Spring Framework
Hibernate Framework

=== Iterate over a LinkedList using descendingIterator() ===
Hibernate Framework
Spring Framework
Java EE
Core Java
C++
C

=== Iterate over a LinkedList using listIterator() ===
Hibernate Framework
Spring Framework
Java EE
Core Java
C++
C

=== Iterate over a LinkedList using simple for-each loop ===
C
C++
Core Java
Java EE
Spring Framework
Hibernate Framework

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