1. Introduction

LinkedHashSet is a part of the Java Collections Framework and resides in the java.util package. It’s an ordered version of HashSet that maintains a doubly-linked list across all elements. This ensures that the order of the elements remains the same as their insertion order. In this tutorial, we will delve into the CRUD (Create, Read, Update, Delete) operations applicable to a LinkedHashSet.

2. Program Steps

1. Initialize a LinkedHashSet.

2. Populate the LinkedHashSet with elements (Create).

3. Check if a specific element exists within the LinkedHashSet (Read).

4. For the Update operation, since duplicates are not permitted in a LinkedHashSet, we’ll first eliminate an old element and then append a new one.

5. Erase elements from the LinkedHashSet.

6. Exhibit the final state of the LinkedHashSet.

3. Code Program

import java.util.LinkedHashSet;

public class LinkedHashSetCRUDExample {
    public static void main(String[] args) {
        // 1. Initialize a LinkedHashSet
        LinkedHashSet<String> colors = new LinkedHashSet<>();

        // 2. Populate the LinkedHashSet with elements (Create)
        colors.add("Red");
        colors.add("Blue");
        colors.add("Green");
        System.out.println("After adding elements: " + colors);

        // 3. Check if a specific element exists within the LinkedHashSet (Read)
        boolean hasRed = colors.contains("Red");
        System.out.println("Contains Red? " + hasRed);

        // 4. Update operation: remove an element and append a new one
        colors.remove("Blue");
        colors.add("Yellow");
        System.out.println("After updating elements: " + colors);

        // 5. Erase elements from the LinkedHashSet
        colors.remove("Green");
        System.out.println("After deleting Green: " + colors);

        // 6. Exhibit the final state of the LinkedHashSet
        System.out.println("Resultant LinkedHashSet: " + colors);
    }
}

Output:

After adding elements: [Red, Blue, Green]
Contains Red? true
After updating elements: [Red, Green, Yellow]
After deleting Green: [Red, Yellow]
Resultant LinkedHashSet: [Red, Yellow]

4. Step By Step Explanation

1. We start by creating an empty LinkedHashSet named colors.

2. By employing the add method, three colors are introduced into the set.

3. The contains method assists in verifying the presence of a certain item in the set.

4. Due to the non-acceptance of duplicates in a LinkedHashSet, the update process demands the removal of an old item using the remove method, followed by the inclusion of a new one via the add method.

5. The remove method is also utilized for the deletion of elements.

6. At various checkpoints, the state of the LinkedHashSet is displayed to monitor the transformations.

This example offers a deep dive into the basic CRUD operations on a LinkedHashSet in Java, underscoring its distinctive features compared to a regular HashSet.