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:

import java.util.*;  
class TestCollection10{  
 public static void main(String args[]){  
 
  LinkedHashSet<String> al=new LinkedHashSet<String>();  
  al.add("Ravi");  
  al.add("Vijay");  
  al.add("Ravi");  
  al.add("Ajay");  
 
  Iterator<String> itr=al.iterator();
  while(itr.hasNext()){  
   System.out.println(itr.next());
  }
 }
}  

Output:>Ravi
       Vijay
       Ajay