LinkedHashSet

01What is LinkedHashSet?

LinkedHashSet is a variation of HashSet that maintains the insertion order of elements — meaning elements appear in the same order they were added, while still preventing duplicates.

02Why is it used?

It's useful when you need the uniqueness guarantee of a Set, but also want to preserve a predictable, consistent order of elements, unlike a regular HashSet.

03Real-Life Example

Think of a guest list at an event where each guest's name is unique, and names are recorded in exactly the order they registered. LinkedHashSet preserves this registration order while ensuring no repeated names.

java
LinkedHashSet<DataType> setName = new LinkedHashSet<>();

java
import java.util.LinkedHashSet;

public class LinkedHashSetDemo {
    public static void main(String[] args) {
        LinkedHashSet<String> visitors = new LinkedHashSet<>();
        visitors.add("Karan");
        visitors.add("Divya");
        visitors.add("Karan"); // duplicate, ignored
        System.out.println(visitors);
    }
}

[Karan, Divya]