Java LinkedHashSet class:

• contains unique elements only like HashSet. It extends HashSet class and implements Set interface.
• maintains insertion order.

Hierarchy of LinkedHashSet class:

Example of LinkedHashSet class:

1. import java.util.*;  
2. class TestCollection10{  
3.  public static void main(String args[]){  
4.    
5.   LinkedHashSet<String> al=new LinkedHashSet<String>();  
6.   al.add("Ravi");  
7.   al.add("Vijay");  
8.   al.add("Ravi");  
9.   al.add("Ajay");  
10.   
11.   Iterator<String> itr=al.iterator();  
12.   while(itr.hasNext()){  
13.    System.out.println(itr.next());  
14.   }  
15.  }  
16. }  

Output:>Ravi
       Vijay
       Ajay