Java Sequenced Collection

The Sequenced Collection feature was introduced in Java 9.

Purpose

The purpose of Sequenced Collection is to provide a way to create collections that maintain the order of elements based on the order in which they were added.

Real-time Use Case

Imagine a scenario where you need to maintain the order of tasks in a to-do list application. You want to display the tasks in the order they were added by the user.

In this case, you can use a Sequenced Collection to store the tasks, ensuring that they are displayed in the correct order.

Executable Code

import java.util.*;

public class Main {
    public static void main(String[] args) {
        // Example using SequencedMap
        System.out.println("Example using SequencedMap:");
        Map<String, String> sequencedMap = new SequencedMap<>();
        sequencedMap.put("1", "One");
        sequencedMap.put("2", "Two");
        sequencedMap.put("3", "Three");

        System.out.println("Entries in the order they were added:");
        for (Map.Entry<String, String> entry : sequencedMap.entrySet()) {
            System.out.println(entry.getKey() + ": " + entry.getValue());
        }

        // Example using SequencedSet
        System.out.println("\nExample using SequencedSet:");
        Set<String> sequencedSet = new SequencedSet<>();
        sequencedSet.add("Apple");
        sequencedSet.add("Banana");
        sequencedSet.add("Orange");

        System.out.println("Elements in the order they were added:");
        for (String element : sequencedSet) {
            System.out.println(element);
        }
    }
}