LinkedHashSet in Java with Examples

import java.util.LinkedHashSet;

public class LinkedHashSetCreation {
    public static void main(String[] args) {
        // Create a LinkedHashSet of Strings
        LinkedHashSet<String> linkedHashSet = new LinkedHashSet<>();
        
        // Displaying the LinkedHashSet (which is empty at this point)
        System.out.println("LinkedHashSet elements: " + linkedHashSet);
    }
}

// Java Program to Illustrate LinkedHashSet

// Importing required classes
import java.util.LinkedHashSet;

// Main class
// LinkedHashSetExample
public class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Creating an empty LinkedHashSet of string type
        LinkedHashSet<String> linkedset
            = new LinkedHashSet<String>();

        // Adding element to LinkedHashSet
        // using add() method
        linkedset.add("A");
        linkedset.add("B");
        linkedset.add("C");
        linkedset.add("D");

        // Note: This will not add new element
        // as A already exists
        linkedset.add("A");
        linkedset.add("E");

        // Getting size of LinkedHashSet
        // using size() method
        System.out.println("Size of LinkedHashSet = "
                           + linkedset.size());

        System.out.println("Original LinkedHashSet:"
                           + linkedset);

        // Removing existing entry from above Set
        // using remove() method
        System.out.println("Removing D from LinkedHashSet: "
                           + linkedset.remove("D"));

        // Removing existing entry from above Set
        // that does not exist in Set
        System.out.println(
            "Trying to Remove Z which is not "
            + "present: " + linkedset.remove("Z"));

        // Checking for element whether it is present inside
        // Set or not using contains() method
        System.out.println("Checking if A is present="
                           + linkedset.contains("A"));

        // Noew lastly printing the updated LinkedHashMap
        System.out.println("Updated LinkedHashSet: "
                           + linkedset);
    }
}

// Java Program to Add Elements to LinkedHashSet

// Importing required classes
import java.io.*;
import java.util.*;

// Main class
// AddingElementsToLinkedHashSet
class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Creating an empty LinkedHashSet
        LinkedHashSet<String> hs = new LinkedHashSet<String>();

        // Adding elements to above Set
        // using add() method

        // Note: Insertion order is maintained
        hs.add("Geek");
        hs.add("For");
        hs.add("Geeks");

        // Printing elements of Set
        System.out.println("LinkedHashSet : " + hs);
    }
}

// Java program to Remove Elements from LinkedHashSet

// Importing required classes
import java.io.*;
import java.util.*;

// Main class
// RemoveElementsFromLinkedHashSet
class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Creating an empty LinekdhashSet of string type
        LinkedHashSet<String> hs
            = new LinkedHashSet<String>();

        // Adding elements to above Set
        // using add() method
        hs.add("Geek");
        hs.add("For");
        hs.add("Geeks");
        hs.add("A");
        hs.add("B");
        hs.add("Z");

        // Printing all above elements to the console
        System.out.println("Initial HashSet " + hs);

        // Removing the element from above Set
        hs.remove("B");

        // Again removing the element
        System.out.println("After removing element " + hs);

        // Returning false if the element is not present
        System.out.println(hs.remove("AC"));
    }
}

// Java Program to Illustrate Iterating over LinkedHashSet

// Importing required classes
import java.io.*;
import java.util.*;

// Main class
// IteratingLinkedHashSet
class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Instantiate an object of Set
        // Since LinkedHashSet implements Set
        // Set points to LinkedHashSet
        Set<String> hs = new LinkedHashSet<String>();

        // Adding elements to above Set
        // using add() method
        hs.add("Geek");
        hs.add("For");
        hs.add("Geeks");
        hs.add("A");
        hs.add("B");
        hs.add("Z");

        // Iterating though the LinkedHashSet
        // using iterators
        Iterator itr = hs.iterator();

        while (itr.hasNext())
            System.out.print(itr.next() + ", ");

        // New line
        System.out.println();

        // Using enhanced for loop for iteration
        for (String s : hs)
            System.out.print(s + ", ");
        System.out.println();
    }
}